extension_webkit_preferences.cc revision 2a99a7e74a7f215066514fe81d2bfa6639d9eddd 
1// Copyright (c) 2012 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 "chrome/browser/extensions/extension_webkit_preferences.h"
6
7#include "base/command_line.h"
8#include "chrome/common/chrome_switches.h"
9#include "chrome/common/extensions/extension.h"
10#include "chrome/common/extensions/manifest.h"
11#include "webkit/glue/webpreferences.h"
12
13namespace extension_webkit_preferences {
14
15void SetPreferences(const extensions::Extension* extension,
16                    chrome::ViewType render_view_type,
17                    webkit_glue::WebPreferences* webkit_prefs) {
18  if (!extension)
19    return;
20
21  if (!extension->is_hosted_app()) {
22    // Extensions are trusted so we override any user preferences for disabling
23    // javascript or images.
24    webkit_prefs->loads_images_automatically = true;
25    webkit_prefs->javascript_enabled = true;
26
27    // Tabs aren't typically allowed to close windows. But extensions shouldn't
28    // be subject to that.
29    webkit_prefs->allow_scripts_to_close_windows = true;
30
31    // Disable gpu acceleration for extension background pages to avoid
32    // unecessarily creating a compositor context for them.
33    if (render_view_type == chrome::VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {
34      webkit_prefs->accelerated_compositing_enabled = false;
35      webkit_prefs->force_compositing_mode = false;
36    }
37  }
38
39  if (extension->is_platform_app()) {
40    webkit_prefs->databases_enabled = false;
41    webkit_prefs->local_storage_enabled = false;
42    webkit_prefs->sync_xhr_in_documents_enabled = false;
43    webkit_prefs->cookie_enabled = false;
44  }
45
46  // Enable WebGL features that regular pages can't access, since they add
47  // more risk of fingerprinting.
48  webkit_prefs->privileged_webgl_extensions_enabled = true;
49
50  // If this is a component extension, then apply the same poliy for
51  // accelerated compositing as for chrome: URLs (from
52  // WebContents::GetWebkitPrefs).  This is important for component extensions
53  // like the file manager which are sometimes loaded using chrome: URLs and
54  // sometimes loaded with chrome-extension: URLs - we should expect the
55  // performance characteristics to be similar in both cases.
56  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
57  if (extension->location() == extensions::Manifest::COMPONENT &&
58      !command_line.HasSwitch(switches::kAllowWebUICompositing)) {
59    webkit_prefs->accelerated_compositing_enabled = false;
60    webkit_prefs->accelerated_2d_canvas_enabled = false;
61  }
62}
63
64}  // extension_webkit_preferences
65