dispatcher.cc revision 010d83a9304c5a91596085d917d248abff47903a 
1// Copyright 2014 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "extensions/renderer/dispatcher.h"
6
7#include "base/callback.h"
8#include "base/command_line.h"
9#include "base/debug/alias.h"
10#include "base/memory/scoped_ptr.h"
11#include "base/metrics/user_metrics_action.h"
12#include "base/strings/string_piece.h"
13#include "base/strings/string_split.h"
14#include "base/strings/string_util.h"
15#include "base/values.h"
16#include "content/public/common/content_switches.h"
17#include "content/public/common/url_constants.h"
18#include "content/public/renderer/render_thread.h"
19#include "content/public/renderer/render_view.h"
20#include "content/public/renderer/v8_value_converter.h"
21#include "extensions/common/api/messaging/message.h"
22#include "extensions/common/constants.h"
23#include "extensions/common/extension.h"
24#include "extensions/common/extension_api.h"
25#include "extensions/common/extension_messages.h"
26#include "extensions/common/extension_urls.h"
27#include "extensions/common/features/feature.h"
28#include "extensions/common/features/feature_provider.h"
29#include "extensions/common/manifest.h"
30#include "extensions/common/manifest_constants.h"
31#include "extensions/common/manifest_handlers/background_info.h"
32#include "extensions/common/manifest_handlers/externally_connectable.h"
33#include "extensions/common/manifest_handlers/sandboxed_page_info.h"
34#include "extensions/common/message_bundle.h"
35#include "extensions/common/permissions/permission_set.h"
36#include "extensions/common/permissions/permissions_data.h"
37#include "extensions/common/switches.h"
38#include "extensions/common/view_type.h"
39#include "extensions/renderer/api_activity_logger.h"
40#include "extensions/renderer/api_definitions_natives.h"
41#include "extensions/renderer/app_runtime_custom_bindings.h"
42#include "extensions/renderer/binding_generating_native_handler.h"
43#include "extensions/renderer/blob_native_handler.h"
44#include "extensions/renderer/content_watcher.h"
45#include "extensions/renderer/context_menus_custom_bindings.h"
46#include "extensions/renderer/css_native_handler.h"
47#include "extensions/renderer/dispatcher_delegate.h"
48#include "extensions/renderer/document_custom_bindings.h"
49#include "extensions/renderer/dom_activity_logger.h"
50#include "extensions/renderer/event_bindings.h"
51#include "extensions/renderer/extension_groups.h"
52#include "extensions/renderer/extension_helper.h"
53#include "extensions/renderer/extensions_renderer_client.h"
54#include "extensions/renderer/file_system_natives.h"
55#include "extensions/renderer/i18n_custom_bindings.h"
56#include "extensions/renderer/id_generator_custom_bindings.h"
57#include "extensions/renderer/lazy_background_page_native_handler.h"
58#include "extensions/renderer/logging_native_handler.h"
59#include "extensions/renderer/messaging_bindings.h"
60#include "extensions/renderer/module_system.h"
61#include "extensions/renderer/print_native_handler.h"
62#include "extensions/renderer/process_info_native_handler.h"
63#include "extensions/renderer/render_view_observer_natives.h"
64#include "extensions/renderer/request_sender.h"
65#include "extensions/renderer/runtime_custom_bindings.h"
66#include "extensions/renderer/safe_builtins.h"
67#include "extensions/renderer/script_context.h"
68#include "extensions/renderer/script_context_set.h"
69#include "extensions/renderer/send_request_natives.h"
70#include "extensions/renderer/set_icon_natives.h"
71#include "extensions/renderer/test_features_native_handler.h"
72#include "extensions/renderer/user_gestures_native_handler.h"
73#include "extensions/renderer/user_script_slave.h"
74#include "extensions/renderer/utils_native_handler.h"
75#include "extensions/renderer/v8_context_native_handler.h"
76#include "grit/common_resources.h"
77#include "grit/renderer_resources.h"
78#include "third_party/WebKit/public/platform/WebString.h"
79#include "third_party/WebKit/public/platform/WebURLRequest.h"
80#include "third_party/WebKit/public/web/WebCustomElement.h"
81#include "third_party/WebKit/public/web/WebDataSource.h"
82#include "third_party/WebKit/public/web/WebDocument.h"
83#include "third_party/WebKit/public/web/WebFrame.h"
84#include "third_party/WebKit/public/web/WebRuntimeFeatures.h"
85#include "third_party/WebKit/public/web/WebScopedUserGesture.h"
86#include "third_party/WebKit/public/web/WebSecurityPolicy.h"
87#include "third_party/WebKit/public/web/WebView.h"
88#include "ui/base/layout.h"
89#include "ui/base/resource/resource_bundle.h"
90#include "v8/include/v8.h"
91
92using base::UserMetricsAction;
93using blink::WebDataSource;
94using blink::WebDocument;
95using blink::WebFrame;
96using blink::WebScopedUserGesture;
97using blink::WebSecurityPolicy;
98using blink::WebString;
99using blink::WebVector;
100using blink::WebView;
101using content::RenderThread;
102using content::RenderView;
103
104namespace extensions {
105
106namespace {
107
108static const int64 kInitialExtensionIdleHandlerDelayMs = 5 * 1000;
109static const int64 kMaxExtensionIdleHandlerDelayMs = 5 * 60 * 1000;
110static const char kEventDispatchFunction[] = "dispatchEvent";
111static const char kOnSuspendEvent[] = "runtime.onSuspend";
112static const char kOnSuspendCanceledEvent[] = "runtime.onSuspendCanceled";
113
114// Returns the global value for "chrome" from |context|. If one doesn't exist
115// creates a new object for it.
116//
117// Note that this isn't necessarily an object, since webpages can write, for
118// example, "window.chrome = true".
119v8::Handle<v8::Value> GetOrCreateChrome(ScriptContext* context) {
120  v8::Handle<v8::String> chrome_string(
121      v8::String::NewFromUtf8(context->isolate(), "chrome"));
122  v8::Handle<v8::Object> global(context->v8_context()->Global());
123  v8::Handle<v8::Value> chrome(global->Get(chrome_string));
124  if (chrome->IsUndefined()) {
125    chrome = v8::Object::New(context->isolate());
126    global->Set(chrome_string, chrome);
127  }
128  return chrome;
129}
130
131// Returns |value| cast to an object if possible, else an empty handle.
132v8::Handle<v8::Object> AsObjectOrEmpty(v8::Handle<v8::Value> value) {
133  return value->IsObject() ? value.As<v8::Object>() : v8::Handle<v8::Object>();
134}
135
136// Calls a method |method_name| in a module |module_name| belonging to the
137// module system from |context|. Intended as a callback target from
138// ScriptContextSet::ForEach.
139void CallModuleMethod(const std::string& module_name,
140                      const std::string& method_name,
141                      const base::ListValue* args,
142                      ScriptContext* context) {
143  v8::HandleScope handle_scope(context->isolate());
144  v8::Context::Scope context_scope(context->v8_context());
145
146  scoped_ptr<content::V8ValueConverter> converter(
147      content::V8ValueConverter::create());
148
149  std::vector<v8::Handle<v8::Value> > arguments;
150  for (base::ListValue::const_iterator it = args->begin(); it != args->end();
151       ++it) {
152    arguments.push_back(converter->ToV8Value(*it, context->v8_context()));
153  }
154
155  context->module_system()->CallModuleMethod(
156      module_name, method_name, &arguments);
157}
158
159// This handles the "chrome." root API object in script contexts.
160class ChromeNativeHandler : public ObjectBackedNativeHandler {
161 public:
162  explicit ChromeNativeHandler(ScriptContext* context)
163      : ObjectBackedNativeHandler(context) {
164    RouteFunction(
165        "GetChrome",
166        base::Bind(&ChromeNativeHandler::GetChrome, base::Unretained(this)));
167  }
168
169  void GetChrome(const v8::FunctionCallbackInfo<v8::Value>& args) {
170    args.GetReturnValue().Set(GetOrCreateChrome(context()));
171  }
172};
173
174}  // namespace
175
176Dispatcher::Dispatcher(DispatcherDelegate* delegate)
177    : delegate_(delegate),
178      content_watcher_(new ContentWatcher()),
179      source_map_(&ResourceBundle::GetSharedInstance()),
180      v8_schema_registry_(new V8SchemaRegistry),
181      is_webkit_initialized_(false) {
182  const CommandLine& command_line = *(CommandLine::ForCurrentProcess());
183  is_extension_process_ =
184      command_line.HasSwitch(extensions::switches::kExtensionProcess) ||
185      command_line.HasSwitch(::switches::kSingleProcess);
186
187  if (is_extension_process_) {
188    RenderThread::Get()->SetIdleNotificationDelayInMs(
189        kInitialExtensionIdleHandlerDelayMs);
190  }
191
192  RenderThread::Get()->RegisterExtension(SafeBuiltins::CreateV8Extension());
193
194  user_script_slave_.reset(new UserScriptSlave(&extensions_));
195  request_sender_.reset(new RequestSender(this));
196  PopulateSourceMap();
197}
198
199Dispatcher::~Dispatcher() {
200}
201
202bool Dispatcher::IsExtensionActive(const std::string& extension_id) const {
203  bool is_active =
204      active_extension_ids_.find(extension_id) != active_extension_ids_.end();
205  if (is_active)
206    CHECK(extensions_.Contains(extension_id));
207  return is_active;
208}
209
210std::string Dispatcher::GetExtensionID(const WebFrame* frame, int world_id) {
211  if (world_id != 0) {
212    // Isolated worlds (content script).
213    return user_script_slave_->GetExtensionIdForIsolatedWorld(world_id);
214  }
215
216  // TODO(kalman): Delete this check.
217  if (frame->document().securityOrigin().isUnique())
218    return std::string();
219
220  // Extension pages (chrome-extension:// URLs).
221  GURL frame_url = ScriptContext::GetDataSourceURLForFrame(frame);
222  return extensions_.GetExtensionOrAppIDByURL(frame_url);
223}
224
225void Dispatcher::DidCreateScriptContext(
226    WebFrame* frame,
227    const v8::Handle<v8::Context>& v8_context,
228    int extension_group,
229    int world_id) {
230#if !defined(ENABLE_EXTENSIONS)
231  return;
232#endif
233
234  std::string extension_id = GetExtensionID(frame, world_id);
235
236  const Extension* extension = extensions_.GetByID(extension_id);
237  if (!extension && !extension_id.empty()) {
238    // There are conditions where despite a context being associated with an
239    // extension, no extension actually gets found.  Ignore "invalid" because
240    // CSP blocks extension page loading by switching the extension ID to
241    // "invalid". This isn't interesting.
242    if (extension_id != "invalid") {
243      LOG(ERROR) << "Extension \"" << extension_id << "\" not found";
244      RenderThread::Get()->RecordAction(
245          UserMetricsAction("ExtensionNotFound_ED"));
246    }
247
248    extension_id = "";
249  }
250
251  Feature::Context context_type =
252      ClassifyJavaScriptContext(extension,
253                                extension_group,
254                                ScriptContext::GetDataSourceURLForFrame(frame),
255                                frame->document().securityOrigin());
256
257  ScriptContext* context =
258      delegate_->CreateScriptContext(v8_context, frame, extension, context_type)
259          .release();
260  script_context_set_.Add(context);
261
262  if (extension) {
263    InitOriginPermissions(extension, context_type);
264  }
265
266  {
267    scoped_ptr<ModuleSystem> module_system(
268        new ModuleSystem(context, &source_map_));
269    context->set_module_system(module_system.Pass());
270  }
271  ModuleSystem* module_system = context->module_system();
272
273  // Enable natives in startup.
274  ModuleSystem::NativesEnabledScope natives_enabled_scope(module_system);
275
276  RegisterNativeHandlers(module_system, context);
277
278  // chrome.Event is part of the public API (although undocumented). Make it
279  // lazily evalulate to Event from event_bindings.js. For extensions only
280  // though, not all webpages!
281  if (context->extension()) {
282    v8::Handle<v8::Object> chrome = AsObjectOrEmpty(GetOrCreateChrome(context));
283    if (!chrome.IsEmpty())
284      module_system->SetLazyField(chrome, "Event", kEventBindings, "Event");
285  }
286
287  UpdateBindingsForContext(context);
288
289  bool is_within_platform_app = IsWithinPlatformApp();
290  // Inject custom JS into the platform app context.
291  if (is_within_platform_app) {
292    module_system->Require("platformApp");
293  }
294
295  delegate_->RequireAdditionalModules(
296      module_system, extension, context_type, is_within_platform_app);
297
298  VLOG(1) << "Num tracked contexts: " << script_context_set_.size();
299}
300
301void Dispatcher::WillReleaseScriptContext(
302    WebFrame* frame,
303    const v8::Handle<v8::Context>& v8_context,
304    int world_id) {
305  ScriptContext* context = script_context_set_.GetByV8Context(v8_context);
306  if (!context)
307    return;
308
309  context->DispatchOnUnloadEvent();
310  // TODO(kalman): add an invalidation observer interface to ScriptContext.
311  request_sender_->InvalidateSource(context);
312
313  script_context_set_.Remove(context);
314  VLOG(1) << "Num tracked contexts: " << script_context_set_.size();
315}
316
317void Dispatcher::DidCreateDocumentElement(blink::WebFrame* frame) {
318  if (IsWithinPlatformApp()) {
319    // WebKit doesn't let us define an additional user agent stylesheet, so we
320    // insert the default platform app stylesheet into all documents that are
321    // loaded in each app.
322    std::string stylesheet = ResourceBundle::GetSharedInstance()
323                                 .GetRawDataResource(IDR_PLATFORM_APP_CSS)
324                                 .as_string();
325    ReplaceFirstSubstringAfterOffset(
326        &stylesheet, 0, "$FONTFAMILY", system_font_family_);
327    ReplaceFirstSubstringAfterOffset(
328        &stylesheet, 0, "$FONTSIZE", system_font_size_);
329    frame->document().insertStyleSheet(WebString::fromUTF8(stylesheet));
330  }
331
332  content_watcher_->DidCreateDocumentElement(frame);
333}
334
335void Dispatcher::DidMatchCSS(
336    blink::WebFrame* frame,
337    const blink::WebVector<blink::WebString>& newly_matching_selectors,
338    const blink::WebVector<blink::WebString>& stopped_matching_selectors) {
339  content_watcher_->DidMatchCSS(
340      frame, newly_matching_selectors, stopped_matching_selectors);
341}
342
343void Dispatcher::OnExtensionResponse(int request_id,
344                                     bool success,
345                                     const base::ListValue& response,
346                                     const std::string& error) {
347  request_sender_->HandleResponse(request_id, success, response, error);
348}
349
350bool Dispatcher::CheckContextAccessToExtensionAPI(
351    const std::string& function_name,
352    ScriptContext* context) const {
353  if (!context) {
354    DLOG(ERROR) << "Not in a v8::Context";
355    return false;
356  }
357
358  if (!context->extension()) {
359    context->isolate()->ThrowException(v8::Exception::Error(
360        v8::String::NewFromUtf8(context->isolate(), "Not in an extension.")));
361    return false;
362  }
363
364  // Theoretically we could end up with bindings being injected into sandboxed
365  // frames, for example content scripts. Don't let them execute API functions.
366  blink::WebFrame* frame = context->web_frame();
367  if (IsSandboxedPage(ScriptContext::GetDataSourceURLForFrame(frame))) {
368    static const char kMessage[] =
369        "%s cannot be used within a sandboxed frame.";
370    std::string error_msg = base::StringPrintf(kMessage, function_name.c_str());
371    context->isolate()->ThrowException(v8::Exception::Error(
372        v8::String::NewFromUtf8(context->isolate(), error_msg.c_str())));
373    return false;
374  }
375
376  Feature::Availability availability = context->GetAvailability(function_name);
377  if (!availability.is_available()) {
378    context->isolate()->ThrowException(
379        v8::Exception::Error(v8::String::NewFromUtf8(
380            context->isolate(), availability.message().c_str())));
381  }
382
383  return availability.is_available();
384}
385
386void Dispatcher::DispatchEvent(const std::string& extension_id,
387                               const std::string& event_name) const {
388  base::ListValue args;
389  args.Set(0, new base::StringValue(event_name));
390  args.Set(1, new base::ListValue());
391
392  // Needed for Windows compilation, since kEventBindings is declared extern.
393  const char* local_event_bindings = kEventBindings;
394  script_context_set_.ForEach(extension_id,
395                              NULL,  // all render views
396                              base::Bind(&CallModuleMethod,
397                                         local_event_bindings,
398                                         kEventDispatchFunction,
399                                         &args));
400}
401
402void Dispatcher::InvokeModuleSystemMethod(content::RenderView* render_view,
403                                          const std::string& extension_id,
404                                          const std::string& module_name,
405                                          const std::string& function_name,
406                                          const base::ListValue& args,
407                                          bool user_gesture) {
408  scoped_ptr<WebScopedUserGesture> web_user_gesture;
409  if (user_gesture)
410    web_user_gesture.reset(new WebScopedUserGesture);
411
412  script_context_set_.ForEach(
413      extension_id,
414      render_view,
415      base::Bind(&CallModuleMethod, module_name, function_name, &args));
416
417  // Reset the idle handler each time there's any activity like event or message
418  // dispatch, for which Invoke is the chokepoint.
419  if (is_extension_process_) {
420    RenderThread::Get()->ScheduleIdleHandler(
421        kInitialExtensionIdleHandlerDelayMs);
422  }
423
424  // Tell the browser process when an event has been dispatched with a lazy
425  // background page active.
426  const Extension* extension = extensions_.GetByID(extension_id);
427  if (extension && BackgroundInfo::HasLazyBackgroundPage(extension) &&
428      module_name == kEventBindings &&
429      function_name == kEventDispatchFunction) {
430    RenderView* background_view =
431        ExtensionHelper::GetBackgroundPage(extension_id);
432    if (background_view) {
433      background_view->Send(
434          new ExtensionHostMsg_EventAck(background_view->GetRoutingID()));
435    }
436  }
437}
438
439void Dispatcher::ClearPortData(int port_id) {
440  // Only the target port side has entries in |port_to_tab_id_map_|. If
441  // |port_id| is a source port, std::map::erase() will just silently fail
442  // here as a no-op.
443  port_to_tab_id_map_.erase(port_id);
444}
445
446bool Dispatcher::OnControlMessageReceived(const IPC::Message& message) {
447  bool handled = true;
448  IPC_BEGIN_MESSAGE_MAP(Dispatcher, message)
449  IPC_MESSAGE_HANDLER(ExtensionMsg_ActivateExtension, OnActivateExtension)
450  IPC_MESSAGE_HANDLER(ExtensionMsg_CancelSuspend, OnCancelSuspend)
451  IPC_MESSAGE_HANDLER(ExtensionMsg_ClearTabSpecificPermissions,
452                      OnClearTabSpecificPermissions)
453  IPC_MESSAGE_HANDLER(ExtensionMsg_DeliverMessage, OnDeliverMessage)
454  IPC_MESSAGE_HANDLER(ExtensionMsg_DispatchOnConnect, OnDispatchOnConnect)
455  IPC_MESSAGE_HANDLER(ExtensionMsg_DispatchOnDisconnect, OnDispatchOnDisconnect)
456  IPC_MESSAGE_HANDLER(ExtensionMsg_Loaded, OnLoaded)
457  IPC_MESSAGE_HANDLER(ExtensionMsg_MessageInvoke, OnMessageInvoke)
458  IPC_MESSAGE_HANDLER(ExtensionMsg_SetChannel, OnSetChannel)
459  IPC_MESSAGE_HANDLER(ExtensionMsg_SetFunctionNames, OnSetFunctionNames)
460  IPC_MESSAGE_HANDLER(ExtensionMsg_SetScriptingWhitelist,
461                      OnSetScriptingWhitelist)
462  IPC_MESSAGE_HANDLER(ExtensionMsg_SetSystemFont, OnSetSystemFont)
463  IPC_MESSAGE_HANDLER(ExtensionMsg_ShouldSuspend, OnShouldSuspend)
464  IPC_MESSAGE_HANDLER(ExtensionMsg_Suspend, OnSuspend)
465  IPC_MESSAGE_HANDLER(ExtensionMsg_Unloaded, OnUnloaded)
466  IPC_MESSAGE_HANDLER(ExtensionMsg_UpdatePermissions, OnUpdatePermissions)
467  IPC_MESSAGE_HANDLER(ExtensionMsg_UpdateTabSpecificPermissions,
468                      OnUpdateTabSpecificPermissions)
469  IPC_MESSAGE_HANDLER(ExtensionMsg_UpdateUserScripts, OnUpdateUserScripts)
470  IPC_MESSAGE_HANDLER(ExtensionMsg_UsingWebRequestAPI, OnUsingWebRequestAPI)
471  IPC_MESSAGE_FORWARD(ExtensionMsg_WatchPages,
472                      content_watcher_.get(),
473                      ContentWatcher::OnWatchPages)
474  IPC_MESSAGE_UNHANDLED(handled = false)
475  IPC_END_MESSAGE_MAP()
476
477  return handled;
478}
479
480void Dispatcher::WebKitInitialized() {
481  // For extensions, we want to ensure we call the IdleHandler every so often,
482  // even if the extension keeps up activity.
483  if (is_extension_process_) {
484    forced_idle_timer_.reset(new base::RepeatingTimer<content::RenderThread>);
485    forced_idle_timer_->Start(
486        FROM_HERE,
487        base::TimeDelta::FromMilliseconds(kMaxExtensionIdleHandlerDelayMs),
488        RenderThread::Get(),
489        &RenderThread::IdleHandler);
490  }
491
492  // Initialize host permissions for any extensions that were activated before
493  // WebKit was initialized.
494  for (std::set<std::string>::iterator iter = active_extension_ids_.begin();
495       iter != active_extension_ids_.end();
496       ++iter) {
497    const Extension* extension = extensions_.GetByID(*iter);
498    CHECK(extension);
499  }
500
501  EnableCustomElementWhiteList();
502
503  is_webkit_initialized_ = true;
504}
505
506void Dispatcher::IdleNotification() {
507  if (is_extension_process_) {
508    // Dampen the forced delay as well if the extension stays idle for long
509    // periods of time.
510    int64 forced_delay_ms =
511        std::max(RenderThread::Get()->GetIdleNotificationDelayInMs(),
512                 kMaxExtensionIdleHandlerDelayMs);
513    forced_idle_timer_->Stop();
514    forced_idle_timer_->Start(
515        FROM_HERE,
516        base::TimeDelta::FromMilliseconds(forced_delay_ms),
517        RenderThread::Get(),
518        &RenderThread::IdleHandler);
519  }
520}
521
522void Dispatcher::OnRenderProcessShutdown() {
523  v8_schema_registry_.reset();
524  forced_idle_timer_.reset();
525}
526
527void Dispatcher::OnActivateExtension(const std::string& extension_id) {
528  const Extension* extension = extensions_.GetByID(extension_id);
529  if (!extension) {
530    // Extension was activated but was never loaded. This probably means that
531    // the renderer failed to load it (or the browser failed to tell us when it
532    // did). Failures shouldn't happen, but instead of crashing there (which
533    // executes on all renderers) be conservative and only crash in the renderer
534    // of the extension which failed to load; this one.
535    std::string& error = extension_load_errors_[extension_id];
536    char minidump[256];
537    base::debug::Alias(&minidump);
538    base::snprintf(minidump,
539                   arraysize(minidump),
540                   "e::dispatcher:%s:%s",
541                   extension_id.c_str(),
542                   error.c_str());
543    CHECK(extension) << extension_id << " was never loaded: " << error;
544  }
545
546  active_extension_ids_.insert(extension_id);
547
548  // This is called when starting a new extension page, so start the idle
549  // handler ticking.
550  RenderThread::Get()->ScheduleIdleHandler(kInitialExtensionIdleHandlerDelayMs);
551
552  if (is_webkit_initialized_) {
553    extensions::DOMActivityLogger::AttachToWorld(
554        extensions::DOMActivityLogger::kMainWorldId, extension_id);
555  }
556
557  UpdateActiveExtensions();
558}
559
560void Dispatcher::OnCancelSuspend(const std::string& extension_id) {
561  DispatchEvent(extension_id, kOnSuspendCanceledEvent);
562}
563
564void Dispatcher::OnClearTabSpecificPermissions(
565    int tab_id,
566    const std::vector<std::string>& extension_ids) {
567  delegate_->ClearTabSpecificPermissions(this, tab_id, extension_ids);
568}
569
570void Dispatcher::OnDeliverMessage(int target_port_id, const Message& message) {
571  scoped_ptr<RequestSender::ScopedTabID> scoped_tab_id;
572  std::map<int, int>::const_iterator it =
573      port_to_tab_id_map_.find(target_port_id);
574  if (it != port_to_tab_id_map_.end()) {
575    scoped_tab_id.reset(
576        new RequestSender::ScopedTabID(request_sender(), it->second));
577  }
578
579  MessagingBindings::DeliverMessage(script_context_set_.GetAll(),
580                                    target_port_id,
581                                    message,
582                                    NULL);  // All render views.
583}
584
585void Dispatcher::OnDispatchOnConnect(
586    int target_port_id,
587    const std::string& channel_name,
588    const base::DictionaryValue& source_tab,
589    const ExtensionMsg_ExternalConnectionInfo& info,
590    const std::string& tls_channel_id) {
591  DCHECK(!ContainsKey(port_to_tab_id_map_, target_port_id));
592  DCHECK_EQ(1, target_port_id % 2);  // target renderer ports have odd IDs.
593  int sender_tab_id = -1;
594  source_tab.GetInteger("id", &sender_tab_id);
595  port_to_tab_id_map_[target_port_id] = sender_tab_id;
596
597  MessagingBindings::DispatchOnConnect(script_context_set_.GetAll(),
598                                       target_port_id,
599                                       channel_name,
600                                       source_tab,
601                                       info.source_id,
602                                       info.target_id,
603                                       info.source_url,
604                                       tls_channel_id,
605                                       NULL);  // All render views.
606}
607
608void Dispatcher::OnDispatchOnDisconnect(int port_id,
609                                        const std::string& error_message) {
610  MessagingBindings::DispatchOnDisconnect(script_context_set_.GetAll(),
611                                          port_id,
612                                          error_message,
613                                          NULL);  // All render views.
614}
615
616void Dispatcher::OnLoaded(
617    const std::vector<ExtensionMsg_Loaded_Params>& loaded_extensions) {
618  std::vector<ExtensionMsg_Loaded_Params>::const_iterator i;
619  for (i = loaded_extensions.begin(); i != loaded_extensions.end(); ++i) {
620    std::string error;
621    scoped_refptr<const Extension> extension = i->ConvertToExtension(&error);
622    if (!extension.get()) {
623      extension_load_errors_[i->id] = error;
624      continue;
625    }
626    OnLoadedInternal(extension);
627  }
628  // Update the available bindings for all contexts. These may have changed if
629  // an externally_connectable extension was loaded that can connect to an
630  // open webpage.
631  UpdateBindings("");
632}
633
634void Dispatcher::OnLoadedInternal(scoped_refptr<const Extension> extension) {
635  extensions_.Insert(extension);
636}
637
638void Dispatcher::OnMessageInvoke(const std::string& extension_id,
639                                 const std::string& module_name,
640                                 const std::string& function_name,
641                                 const base::ListValue& args,
642                                 bool user_gesture) {
643  InvokeModuleSystemMethod(
644      NULL, extension_id, module_name, function_name, args, user_gesture);
645}
646
647void Dispatcher::OnSetChannel(int channel) {
648  delegate_->SetChannel(channel);
649}
650
651void Dispatcher::OnSetFunctionNames(const std::vector<std::string>& names) {
652  function_names_.clear();
653  for (size_t i = 0; i < names.size(); ++i)
654    function_names_.insert(names[i]);
655}
656
657void Dispatcher::OnSetScriptingWhitelist(
658    const ExtensionsClient::ScriptingWhitelist& extension_ids) {
659  ExtensionsClient::Get()->SetScriptingWhitelist(extension_ids);
660}
661
662void Dispatcher::OnSetSystemFont(const std::string& font_family,
663                                 const std::string& font_size) {
664  system_font_family_ = font_family;
665  system_font_size_ = font_size;
666}
667
668void Dispatcher::OnShouldSuspend(const std::string& extension_id,
669                                 int sequence_id) {
670  RenderThread::Get()->Send(
671      new ExtensionHostMsg_ShouldSuspendAck(extension_id, sequence_id));
672}
673
674void Dispatcher::OnSuspend(const std::string& extension_id) {
675  // Dispatch the suspend event. This doesn't go through the standard event
676  // dispatch machinery because it requires special handling. We need to let
677  // the browser know when we are starting and stopping the event dispatch, so
678  // that it still considers the extension idle despite any activity the suspend
679  // event creates.
680  DispatchEvent(extension_id, kOnSuspendEvent);
681  RenderThread::Get()->Send(new ExtensionHostMsg_SuspendAck(extension_id));
682}
683
684void Dispatcher::OnUnloaded(const std::string& id) {
685  extensions_.Remove(id);
686  active_extension_ids_.erase(id);
687
688  // If the extension is later reloaded with a different set of permissions,
689  // we'd like it to get a new isolated world ID, so that it can pick up the
690  // changed origin whitelist.
691  user_script_slave_->RemoveIsolatedWorld(id);
692
693  // Invalidate all of the contexts that were removed.
694  // TODO(kalman): add an invalidation observer interface to ScriptContext.
695  ScriptContextSet::ContextSet removed_contexts =
696      script_context_set_.OnExtensionUnloaded(id);
697  for (ScriptContextSet::ContextSet::iterator it = removed_contexts.begin();
698       it != removed_contexts.end();
699       ++it) {
700    request_sender_->InvalidateSource(*it);
701  }
702
703  // Update the available bindings for the remaining contexts. These may have
704  // changed if an externally_connectable extension is unloaded and a webpage
705  // is no longer accessible.
706  UpdateBindings("");
707
708  // Invalidates the messages map for the extension in case the extension is
709  // reloaded with a new messages map.
710  EraseL10nMessagesMap(id);
711
712  // We don't do anything with existing platform-app stylesheets. They will
713  // stay resident, but the URL pattern corresponding to the unloaded
714  // extension's URL just won't match anything anymore.
715}
716
717void Dispatcher::OnUpdatePermissions(
718    const ExtensionMsg_UpdatePermissions_Params& params) {
719  int reason_id = params.reason_id;
720  const std::string& extension_id = params.extension_id;
721  const APIPermissionSet& apis = params.apis;
722  const ManifestPermissionSet& manifest_permissions =
723      params.manifest_permissions;
724  const URLPatternSet& explicit_hosts = params.explicit_hosts;
725  const URLPatternSet& scriptable_hosts = params.scriptable_hosts;
726
727  const Extension* extension = extensions_.GetByID(extension_id);
728  if (!extension)
729    return;
730
731  scoped_refptr<const PermissionSet> delta = new PermissionSet(
732      apis, manifest_permissions, explicit_hosts, scriptable_hosts);
733  scoped_refptr<const PermissionSet> old_active =
734      extension->GetActivePermissions();
735  UpdatedExtensionPermissionsInfo::Reason reason =
736      static_cast<UpdatedExtensionPermissionsInfo::Reason>(reason_id);
737
738  const PermissionSet* new_active = NULL;
739  switch (reason) {
740    case UpdatedExtensionPermissionsInfo::ADDED:
741      new_active = PermissionSet::CreateUnion(old_active.get(), delta.get());
742      break;
743    case UpdatedExtensionPermissionsInfo::REMOVED:
744      new_active =
745          PermissionSet::CreateDifference(old_active.get(), delta.get());
746      break;
747  }
748
749  PermissionsData::SetActivePermissions(extension, new_active);
750  UpdateOriginPermissions(reason, extension, explicit_hosts);
751  UpdateBindings(extension->id());
752}
753
754void Dispatcher::OnUpdateTabSpecificPermissions(
755    int page_id,
756    int tab_id,
757    const std::string& extension_id,
758    const URLPatternSet& origin_set) {
759  delegate_->UpdateTabSpecificPermissions(
760      this, page_id, tab_id, extension_id, origin_set);
761}
762
763void Dispatcher::OnUpdateUserScripts(base::SharedMemoryHandle scripts) {
764  DCHECK(base::SharedMemory::IsHandleValid(scripts)) << "Bad scripts handle";
765  user_script_slave_->UpdateScripts(scripts);
766  UpdateActiveExtensions();
767}
768
769void Dispatcher::OnUsingWebRequestAPI(bool adblock,
770                                      bool adblock_plus,
771                                      bool other_webrequest) {
772  delegate_->HandleWebRequestAPIUsage(adblock, adblock_plus, other_webrequest);
773}
774
775void Dispatcher::UpdateActiveExtensions() {
776  std::set<std::string> active_extensions = active_extension_ids_;
777  user_script_slave_->GetActiveExtensions(&active_extensions);
778  delegate_->OnActiveExtensionsUpdated(active_extensions);
779}
780
781void Dispatcher::InitOriginPermissions(const Extension* extension,
782                                       Feature::Context context_type) {
783  delegate_->InitOriginPermissions(extension, context_type);
784  UpdateOriginPermissions(
785      UpdatedExtensionPermissionsInfo::ADDED,
786      extension,
787      PermissionsData::GetEffectiveHostPermissions(extension));
788}
789
790void Dispatcher::UpdateOriginPermissions(
791    UpdatedExtensionPermissionsInfo::Reason reason,
792    const Extension* extension,
793    const URLPatternSet& origins) {
794  for (URLPatternSet::const_iterator i = origins.begin(); i != origins.end();
795       ++i) {
796    const char* schemes[] = {
797        url::kHttpScheme,
798        url::kHttpsScheme,
799        content::kFileScheme,
800        content::kChromeUIScheme,
801        content::kFtpScheme,
802    };
803    for (size_t j = 0; j < arraysize(schemes); ++j) {
804      if (i->MatchesScheme(schemes[j])) {
805        ((reason == UpdatedExtensionPermissionsInfo::REMOVED)
806             ? WebSecurityPolicy::removeOriginAccessWhitelistEntry
807             : WebSecurityPolicy::addOriginAccessWhitelistEntry)(
808            extension->url(),
809            WebString::fromUTF8(schemes[j]),
810            WebString::fromUTF8(i->host()),
811            i->match_subdomains());
812      }
813    }
814  }
815}
816
817void Dispatcher::EnableCustomElementWhiteList() {
818  blink::WebCustomElement::addEmbedderCustomElementName("webview");
819  // TODO(fsamuel): Add <adview> to the whitelist once it has been converted
820  // into a custom element.
821  blink::WebCustomElement::addEmbedderCustomElementName("browser-plugin");
822}
823
824void Dispatcher::UpdateBindings(const std::string& extension_id) {
825  script_context_set().ForEach(extension_id,
826                               NULL,  // all render views
827                               base::Bind(&Dispatcher::UpdateBindingsForContext,
828                                          base::Unretained(this)));
829}
830
831void Dispatcher::UpdateBindingsForContext(ScriptContext* context) {
832  v8::HandleScope handle_scope(context->isolate());
833  v8::Context::Scope context_scope(context->v8_context());
834
835  // TODO(kalman): Make the bindings registration have zero overhead then run
836  // the same code regardless of context type.
837  switch (context->context_type()) {
838    case Feature::UNSPECIFIED_CONTEXT:
839    case Feature::WEB_PAGE_CONTEXT:
840    case Feature::BLESSED_WEB_PAGE_CONTEXT: {
841      // Web page context; it's too expensive to run the full bindings code.
842      // Hard-code that the app and webstore APIs are available...
843      RegisterBinding("app", context);
844      RegisterBinding("webstore", context);
845
846      // ... and that the runtime API might be available if any extension can
847      // connect to it.
848      bool runtime_is_available = false;
849      for (ExtensionSet::const_iterator it = extensions_.begin();
850           it != extensions_.end();
851           ++it) {
852        ExternallyConnectableInfo* info =
853            static_cast<ExternallyConnectableInfo*>(
854                (*it)->GetManifestData(manifest_keys::kExternallyConnectable));
855        if (info && info->matches.MatchesURL(context->GetURL())) {
856          runtime_is_available = true;
857          break;
858        }
859      }
860      if (runtime_is_available)
861        RegisterBinding("runtime", context);
862      break;
863    }
864
865    case Feature::BLESSED_EXTENSION_CONTEXT:
866    case Feature::UNBLESSED_EXTENSION_CONTEXT:
867    case Feature::CONTENT_SCRIPT_CONTEXT: {
868      // Extension context; iterate through all the APIs and bind the available
869      // ones.
870      FeatureProvider* api_feature_provider = FeatureProvider::GetAPIFeatures();
871      const std::vector<std::string>& apis =
872          api_feature_provider->GetAllFeatureNames();
873      for (std::vector<std::string>::const_iterator it = apis.begin();
874           it != apis.end();
875           ++it) {
876        const std::string& api_name = *it;
877        Feature* feature = api_feature_provider->GetFeature(api_name);
878        DCHECK(feature);
879
880        // Internal APIs are included via require(api_name) from internal code
881        // rather than chrome[api_name].
882        if (feature->IsInternal())
883          continue;
884
885        // If this API has a parent feature (and isn't marked 'noparent'),
886        // then this must be a function or event, so we should not register.
887        if (api_feature_provider->GetParent(feature) != NULL)
888          continue;
889
890        if (context->IsAnyFeatureAvailableToContext(*feature))
891          RegisterBinding(api_name, context);
892      }
893      if (CommandLine::ForCurrentProcess()->HasSwitch(::switches::kTestType)) {
894        RegisterBinding("test", context);
895      }
896      break;
897    }
898  }
899}
900
901void Dispatcher::RegisterBinding(const std::string& api_name,
902                                 ScriptContext* context) {
903  std::string bind_name;
904  v8::Handle<v8::Object> bind_object =
905      GetOrCreateBindObjectIfAvailable(api_name, &bind_name, context);
906
907  // Empty if the bind object failed to be created, probably because the
908  // extension overrode chrome with a non-object, e.g. window.chrome = true.
909  if (bind_object.IsEmpty())
910    return;
911
912  v8::Local<v8::String> v8_api_name =
913      v8::String::NewFromUtf8(context->isolate(), api_name.c_str());
914  if (bind_object->HasRealNamedProperty(v8_api_name)) {
915    // The bind object may already have the property if the API has been
916    // registered before (or if the extension has put something there already,
917    // but, whatevs).
918    //
919    // In the former case, we need to re-register the bindings for the APIs
920    // which the extension now has permissions for (if any), but not touch any
921    // others so that we don't destroy state such as event listeners.
922    //
923    // TODO(kalman): Only register available APIs to make this all moot.
924    if (bind_object->HasRealNamedCallbackProperty(v8_api_name))
925      return;  // lazy binding still there, nothing to do
926    if (bind_object->Get(v8_api_name)->IsObject())
927      return;  // binding has already been fully installed
928  }
929
930  ModuleSystem* module_system = context->module_system();
931  if (!source_map_.Contains(api_name)) {
932    module_system->RegisterNativeHandler(
933        api_name,
934        scoped_ptr<NativeHandler>(new BindingGeneratingNativeHandler(
935            module_system, api_name, "binding")));
936    module_system->SetNativeLazyField(
937        bind_object, bind_name, api_name, "binding");
938  } else {
939    module_system->SetLazyField(bind_object, bind_name, api_name, "binding");
940  }
941}
942
943// NOTE: please use the naming convention "foo_natives" for these.
944void Dispatcher::RegisterNativeHandlers(ModuleSystem* module_system,
945                                        ScriptContext* context) {
946  module_system->RegisterNativeHandler(
947      "chrome", scoped_ptr<NativeHandler>(new ChromeNativeHandler(context)));
948  module_system->RegisterNativeHandler(
949      "lazy_background_page",
950      scoped_ptr<NativeHandler>(new LazyBackgroundPageNativeHandler(context)));
951  module_system->RegisterNativeHandler(
952      "logging", scoped_ptr<NativeHandler>(new LoggingNativeHandler(context)));
953  module_system->RegisterNativeHandler("schema_registry",
954                                       v8_schema_registry_->AsNativeHandler());
955  module_system->RegisterNativeHandler(
956      "print", scoped_ptr<NativeHandler>(new PrintNativeHandler(context)));
957  module_system->RegisterNativeHandler(
958      "test_features",
959      scoped_ptr<NativeHandler>(new TestFeaturesNativeHandler(context)));
960  module_system->RegisterNativeHandler(
961      "user_gestures",
962      scoped_ptr<NativeHandler>(new UserGesturesNativeHandler(context)));
963  module_system->RegisterNativeHandler(
964      "utils", scoped_ptr<NativeHandler>(new UtilsNativeHandler(context)));
965  module_system->RegisterNativeHandler(
966      "v8_context",
967      scoped_ptr<NativeHandler>(new V8ContextNativeHandler(context, this)));
968
969  const Extension* extension = context->extension();
970  int manifest_version = extension ? extension->manifest_version() : 1;
971  bool send_request_disabled =
972      (extension && Manifest::IsUnpackedLocation(extension->location()) &&
973       BackgroundInfo::HasLazyBackgroundPage(extension));
974  module_system->RegisterNativeHandler(
975      "process",
976      scoped_ptr<NativeHandler>(new ProcessInfoNativeHandler(
977          context,
978          context->GetExtensionID(),
979          context->GetContextTypeDescription(),
980          ExtensionsRendererClient::Get()->IsIncognitoProcess(),
981          manifest_version,
982          send_request_disabled)));
983
984  module_system->RegisterNativeHandler(
985      "event_natives",
986      scoped_ptr<NativeHandler>(new EventBindings(this, context)));
987  module_system->RegisterNativeHandler(
988      "messaging_natives",
989      scoped_ptr<NativeHandler>(MessagingBindings::Get(this, context)));
990  module_system->RegisterNativeHandler(
991      "apiDefinitions",
992      scoped_ptr<NativeHandler>(new ApiDefinitionsNatives(this, context)));
993  module_system->RegisterNativeHandler(
994      "sendRequest",
995      scoped_ptr<NativeHandler>(
996          new SendRequestNatives(request_sender_.get(), context)));
997  module_system->RegisterNativeHandler(
998      "setIcon",
999      scoped_ptr<NativeHandler>(
1000          new SetIconNatives(request_sender_.get(), context)));
1001  module_system->RegisterNativeHandler(
1002      "activityLogger",
1003      scoped_ptr<NativeHandler>(new APIActivityLogger(context)));
1004  module_system->RegisterNativeHandler(
1005      "renderViewObserverNatives",
1006      scoped_ptr<NativeHandler>(new RenderViewObserverNatives(context)));
1007
1008  // Natives used by multiple APIs.
1009  module_system->RegisterNativeHandler(
1010      "file_system_natives",
1011      scoped_ptr<NativeHandler>(new FileSystemNatives(context)));
1012
1013  // Custom bindings.
1014  module_system->RegisterNativeHandler(
1015      "app_runtime",
1016      scoped_ptr<NativeHandler>(new AppRuntimeCustomBindings(context)));
1017  module_system->RegisterNativeHandler(
1018      "blob_natives",
1019      scoped_ptr<NativeHandler>(new BlobNativeHandler(context)));
1020  module_system->RegisterNativeHandler(
1021      "context_menus",
1022      scoped_ptr<NativeHandler>(new ContextMenusCustomBindings(context)));
1023  module_system->RegisterNativeHandler(
1024      "css_natives", scoped_ptr<NativeHandler>(new CssNativeHandler(context)));
1025  module_system->RegisterNativeHandler(
1026      "document_natives",
1027      scoped_ptr<NativeHandler>(new DocumentCustomBindings(context)));
1028  module_system->RegisterNativeHandler(
1029      "i18n", scoped_ptr<NativeHandler>(new I18NCustomBindings(context)));
1030  module_system->RegisterNativeHandler(
1031      "id_generator",
1032      scoped_ptr<NativeHandler>(new IdGeneratorCustomBindings(context)));
1033  module_system->RegisterNativeHandler(
1034      "runtime", scoped_ptr<NativeHandler>(new RuntimeCustomBindings(context)));
1035
1036  delegate_->RegisterNativeHandlers(this, module_system, context);
1037}
1038
1039void Dispatcher::PopulateSourceMap() {
1040  // Libraries.
1041  source_map_.RegisterSource("entryIdManager", IDR_ENTRY_ID_MANAGER);
1042  source_map_.RegisterSource(kEventBindings, IDR_EVENT_BINDINGS_JS);
1043  source_map_.RegisterSource("imageUtil", IDR_IMAGE_UTIL_JS);
1044  source_map_.RegisterSource("json_schema", IDR_JSON_SCHEMA_JS);
1045  source_map_.RegisterSource("lastError", IDR_LAST_ERROR_JS);
1046  source_map_.RegisterSource("messaging", IDR_MESSAGING_JS);
1047  source_map_.RegisterSource("messaging_utils", IDR_MESSAGING_UTILS_JS);
1048  source_map_.RegisterSource(kSchemaUtils, IDR_SCHEMA_UTILS_JS);
1049  source_map_.RegisterSource("sendRequest", IDR_SEND_REQUEST_JS);
1050  source_map_.RegisterSource("setIcon", IDR_SET_ICON_JS);
1051  source_map_.RegisterSource("test", IDR_TEST_CUSTOM_BINDINGS_JS);
1052  source_map_.RegisterSource("uncaught_exception_handler",
1053                             IDR_UNCAUGHT_EXCEPTION_HANDLER_JS);
1054  source_map_.RegisterSource("unload_event", IDR_UNLOAD_EVENT_JS);
1055  source_map_.RegisterSource("utils", IDR_UTILS_JS);
1056
1057  // Custom bindings.
1058  source_map_.RegisterSource("app.runtime", IDR_APP_RUNTIME_CUSTOM_BINDINGS_JS);
1059  source_map_.RegisterSource("contextMenus",
1060                             IDR_CONTEXT_MENUS_CUSTOM_BINDINGS_JS);
1061  source_map_.RegisterSource("extension", IDR_EXTENSION_CUSTOM_BINDINGS_JS);
1062  source_map_.RegisterSource("i18n", IDR_I18N_CUSTOM_BINDINGS_JS);
1063  source_map_.RegisterSource("permissions", IDR_PERMISSIONS_CUSTOM_BINDINGS_JS);
1064  source_map_.RegisterSource("runtime", IDR_RUNTIME_CUSTOM_BINDINGS_JS);
1065  source_map_.RegisterSource("binding", IDR_BINDING_JS);
1066
1067  // Custom types sources.
1068  source_map_.RegisterSource("StorageArea", IDR_STORAGE_AREA_JS);
1069
1070  // Platform app sources that are not API-specific..
1071  source_map_.RegisterSource("platformApp", IDR_PLATFORM_APP_JS);
1072
1073  delegate_->PopulateSourceMap(&source_map_);
1074}
1075
1076bool Dispatcher::IsWithinPlatformApp() {
1077  for (std::set<std::string>::iterator iter = active_extension_ids_.begin();
1078       iter != active_extension_ids_.end();
1079       ++iter) {
1080    const Extension* extension = extensions_.GetByID(*iter);
1081    if (extension && extension->is_platform_app())
1082      return true;
1083  }
1084  return false;
1085}
1086
1087// TODO(kalman): This is checking for the wrong thing, it should be checking if
1088// the frame's security origin is unique. The extension sandbox directive is
1089// checked for in extensions/common/manifest_handlers/csp_info.cc.
1090bool Dispatcher::IsSandboxedPage(const GURL& url) const {
1091  if (url.SchemeIs(kExtensionScheme)) {
1092    const Extension* extension = extensions_.GetByID(url.host());
1093    if (extension) {
1094      return SandboxedPageInfo::IsSandboxedPage(extension, url.path());
1095    }
1096  }
1097  return false;
1098}
1099
1100Feature::Context Dispatcher::ClassifyJavaScriptContext(
1101    const Extension* extension,
1102    int extension_group,
1103    const GURL& url,
1104    const blink::WebSecurityOrigin& origin) {
1105  DCHECK_GE(extension_group, 0);
1106  if (extension_group == EXTENSION_GROUP_CONTENT_SCRIPTS) {
1107    return extension ?  // TODO(kalman): when does this happen?
1108               Feature::CONTENT_SCRIPT_CONTEXT
1109                     : Feature::UNSPECIFIED_CONTEXT;
1110  }
1111
1112  // We have an explicit check for sandboxed pages before checking whether the
1113  // extension is active in this process because:
1114  // 1. Sandboxed pages run in the same process as regular extension pages, so
1115  //    the extension is considered active.
1116  // 2. ScriptContext creation (which triggers bindings injection) happens
1117  //    before the SecurityContext is updated with the sandbox flags (after
1118  //    reading the CSP header), so the caller can't check if the context's
1119  //    security origin is unique yet.
1120  if (IsSandboxedPage(url))
1121    return Feature::WEB_PAGE_CONTEXT;
1122
1123  if (extension && IsExtensionActive(extension->id())) {
1124    // |extension| is active in this process, but it could be either a true
1125    // extension process or within the extent of a hosted app. In the latter
1126    // case this would usually be considered a (blessed) web page context,
1127    // unless the extension in question is a component extension, in which case
1128    // we cheat and call it blessed.
1129    return (extension->is_hosted_app() &&
1130            extension->location() != Manifest::COMPONENT)
1131               ? Feature::BLESSED_WEB_PAGE_CONTEXT
1132               : Feature::BLESSED_EXTENSION_CONTEXT;
1133  }
1134
1135  // TODO(kalman): This isUnique() check is wrong, it should be performed as
1136  // part of IsSandboxedPage().
1137  if (!origin.isUnique() && extensions_.ExtensionBindingsAllowed(url)) {
1138    if (!extension)  // TODO(kalman): when does this happen?
1139      return Feature::UNSPECIFIED_CONTEXT;
1140    return extension->is_hosted_app() ? Feature::BLESSED_WEB_PAGE_CONTEXT
1141                                      : Feature::UNBLESSED_EXTENSION_CONTEXT;
1142  }
1143
1144  if (url.is_valid())
1145    return Feature::WEB_PAGE_CONTEXT;
1146
1147  return Feature::UNSPECIFIED_CONTEXT;
1148}
1149
1150v8::Handle<v8::Object> Dispatcher::GetOrCreateObject(
1151    const v8::Handle<v8::Object>& object,
1152    const std::string& field,
1153    v8::Isolate* isolate) {
1154  v8::Handle<v8::String> key = v8::String::NewFromUtf8(isolate, field.c_str());
1155  // If the object has a callback property, it is assumed it is an unavailable
1156  // API, so it is safe to delete. This is checked before GetOrCreateObject is
1157  // called.
1158  if (object->HasRealNamedCallbackProperty(key)) {
1159    object->Delete(key);
1160  } else if (object->HasRealNamedProperty(key)) {
1161    v8::Handle<v8::Value> value = object->Get(key);
1162    CHECK(value->IsObject());
1163    return v8::Handle<v8::Object>::Cast(value);
1164  }
1165
1166  v8::Handle<v8::Object> new_object = v8::Object::New(isolate);
1167  object->Set(key, new_object);
1168  return new_object;
1169}
1170
1171v8::Handle<v8::Object> Dispatcher::GetOrCreateBindObjectIfAvailable(
1172    const std::string& api_name,
1173    std::string* bind_name,
1174    ScriptContext* context) {
1175  std::vector<std::string> split;
1176  base::SplitString(api_name, '.', &split);
1177
1178  v8::Handle<v8::Object> bind_object;
1179
1180  // Check if this API has an ancestor. If the API's ancestor is available and
1181  // the API is not available, don't install the bindings for this API. If
1182  // the API is available and its ancestor is not, delete the ancestor and
1183  // install the bindings for the API. This is to prevent loading the ancestor
1184  // API schema if it will not be needed.
1185  //
1186  // For example:
1187  //  If app is available and app.window is not, just install app.
1188  //  If app.window is available and app is not, delete app and install
1189  //  app.window on a new object so app does not have to be loaded.
1190  FeatureProvider* api_feature_provider = FeatureProvider::GetAPIFeatures();
1191  std::string ancestor_name;
1192  bool only_ancestor_available = false;
1193
1194  for (size_t i = 0; i < split.size() - 1; ++i) {
1195    ancestor_name += (i ? "." : "") + split[i];
1196    if (api_feature_provider->GetFeature(ancestor_name) &&
1197        context->GetAvailability(ancestor_name).is_available() &&
1198        !context->GetAvailability(api_name).is_available()) {
1199      only_ancestor_available = true;
1200      break;
1201    }
1202
1203    if (bind_object.IsEmpty()) {
1204      bind_object = AsObjectOrEmpty(GetOrCreateChrome(context));
1205      if (bind_object.IsEmpty())
1206        return v8::Handle<v8::Object>();
1207    }
1208    bind_object = GetOrCreateObject(bind_object, split[i], context->isolate());
1209  }
1210
1211  if (only_ancestor_available)
1212    return v8::Handle<v8::Object>();
1213
1214  if (bind_name)
1215    *bind_name = split.back();
1216
1217  return bind_object.IsEmpty() ? AsObjectOrEmpty(GetOrCreateChrome(context))
1218                               : bind_object;
1219}
1220
1221}  // namespace extensions
1222