layer.h revision 03b57e008b61dfcb1fbad3aea950ae0e001748b0 
1// Copyright 2010 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#ifndef CC_LAYERS_LAYER_H_
6#define CC_LAYERS_LAYER_H_
7
8#include <set>
9#include <string>
10
11#include "base/callback.h"
12#include "base/memory/ref_counted.h"
13#include "base/observer_list.h"
14#include "cc/animation/layer_animation_controller.h"
15#include "cc/animation/layer_animation_value_observer.h"
16#include "cc/animation/layer_animation_value_provider.h"
17#include "cc/base/cc_export.h"
18#include "cc/base/region.h"
19#include "cc/base/scoped_ptr_vector.h"
20#include "cc/debug/micro_benchmark.h"
21#include "cc/layers/draw_properties.h"
22#include "cc/layers/layer_lists.h"
23#include "cc/layers/layer_position_constraint.h"
24#include "cc/layers/paint_properties.h"
25#include "cc/layers/render_surface.h"
26#include "cc/output/filter_operations.h"
27#include "skia/ext/refptr.h"
28#include "third_party/skia/include/core/SkColor.h"
29#include "third_party/skia/include/core/SkImageFilter.h"
30#include "third_party/skia/include/core/SkPicture.h"
31#include "third_party/skia/include/core/SkXfermode.h"
32#include "ui/gfx/point3_f.h"
33#include "ui/gfx/rect.h"
34#include "ui/gfx/rect_f.h"
35#include "ui/gfx/transform.h"
36
37namespace gfx {
38class BoxF;
39}
40
41namespace base {
42namespace debug {
43class ConvertableToTraceFormat;
44}
45}
46
47namespace cc {
48
49class Animation;
50class AnimationDelegate;
51struct AnimationEvent;
52class CopyOutputRequest;
53class LayerAnimationDelegate;
54class LayerAnimationEventObserver;
55class LayerClient;
56class LayerImpl;
57class LayerTreeHost;
58class LayerTreeImpl;
59class PriorityCalculator;
60class RenderingStatsInstrumentation;
61class ResourceUpdateQueue;
62class ScrollbarLayerInterface;
63class SimpleEnclosedRegion;
64struct AnimationEvent;
65template <typename LayerType>
66class OcclusionTracker;
67
68// Base class for composited layers. Special layer types are derived from
69// this class.
70class CC_EXPORT Layer : public base::RefCounted<Layer>,
71                        public LayerAnimationValueObserver,
72                        public LayerAnimationValueProvider {
73 public:
74  typedef RenderSurfaceLayerList RenderSurfaceListType;
75  typedef LayerList LayerListType;
76  typedef RenderSurface RenderSurfaceType;
77
78  enum LayerIdLabels {
79    INVALID_ID = -1,
80  };
81
82  static scoped_refptr<Layer> Create();
83
84  int id() const { return layer_id_; }
85
86  Layer* RootLayer();
87  Layer* parent() { return parent_; }
88  const Layer* parent() const { return parent_; }
89  void AddChild(scoped_refptr<Layer> child);
90  void InsertChild(scoped_refptr<Layer> child, size_t index);
91  void ReplaceChild(Layer* reference, scoped_refptr<Layer> new_layer);
92  void RemoveFromParent();
93  void RemoveAllChildren();
94  void SetChildren(const LayerList& children);
95  bool HasAncestor(const Layer* ancestor) const;
96
97  const LayerList& children() const { return children_; }
98  Layer* child_at(size_t index) { return children_[index].get(); }
99
100  // This requests the layer and its subtree be rendered and given to the
101  // callback. If the copy is unable to be produced (the layer is destroyed
102  // first), then the callback is called with a NULL/empty result.
103  void RequestCopyOfOutput(scoped_ptr<CopyOutputRequest> request);
104  bool HasCopyRequest() const {
105    return !copy_requests_.empty();
106  }
107
108  virtual void SetBackgroundColor(SkColor background_color);
109  SkColor background_color() const { return background_color_; }
110  // If contents_opaque(), return an opaque color else return a
111  // non-opaque color.  Tries to return background_color(), if possible.
112  SkColor SafeOpaqueBackgroundColor() const;
113
114  // A layer's bounds are in logical, non-page-scaled pixels (however, the
115  // root layer's bounds are in physical pixels).
116  void SetBounds(const gfx::Size& bounds);
117  gfx::Size bounds() const { return bounds_; }
118
119  void SetMasksToBounds(bool masks_to_bounds);
120  bool masks_to_bounds() const { return masks_to_bounds_; }
121
122  void SetMaskLayer(Layer* mask_layer);
123  Layer* mask_layer() { return mask_layer_.get(); }
124  const Layer* mask_layer() const { return mask_layer_.get(); }
125
126  virtual void SetNeedsDisplayRect(const gfx::RectF& dirty_rect);
127  void SetNeedsDisplay() { SetNeedsDisplayRect(gfx::RectF(bounds())); }
128
129  void SetOpacity(float opacity);
130  float opacity() const { return opacity_; }
131  bool OpacityIsAnimating() const;
132  virtual bool OpacityCanAnimateOnImplThread() const;
133
134  void SetBlendMode(SkXfermode::Mode blend_mode);
135  SkXfermode::Mode blend_mode() const { return blend_mode_; }
136
137  bool uses_default_blend_mode() const {
138    return blend_mode_ == SkXfermode::kSrcOver_Mode;
139  }
140
141  // A layer is root for an isolated group when it and all its descendants are
142  // drawn over a black and fully transparent background, creating an isolated
143  // group. It should be used along with SetBlendMode(), in order to restrict
144  // layers within the group to blend with layers outside this group.
145  void SetIsRootForIsolatedGroup(bool root);
146  bool is_root_for_isolated_group() const {
147    return is_root_for_isolated_group_;
148  }
149
150  void SetFilters(const FilterOperations& filters);
151  const FilterOperations& filters() const { return filters_; }
152  bool FilterIsAnimating() const;
153
154  // Background filters are filters applied to what is behind this layer, when
155  // they are viewed through non-opaque regions in this layer. They are used
156  // through the WebLayer interface, and are not exposed to HTML.
157  void SetBackgroundFilters(const FilterOperations& filters);
158  const FilterOperations& background_filters() const {
159    return background_filters_;
160  }
161
162  virtual void SetContentsOpaque(bool opaque);
163  bool contents_opaque() const { return contents_opaque_; }
164
165  void SetPosition(const gfx::PointF& position);
166  gfx::PointF position() const { return position_; }
167
168  void SetIsContainerForFixedPositionLayers(bool container);
169  bool IsContainerForFixedPositionLayers() const;
170
171  void SetPositionConstraint(const LayerPositionConstraint& constraint);
172  const LayerPositionConstraint& position_constraint() const {
173    return position_constraint_;
174  }
175
176  void SetTransform(const gfx::Transform& transform);
177  const gfx::Transform& transform() const { return transform_; }
178  bool TransformIsAnimating() const;
179  bool transform_is_invertible() const { return transform_is_invertible_; }
180
181  void SetTransformOrigin(const gfx::Point3F&);
182  gfx::Point3F transform_origin() { return transform_origin_; }
183
184  void SetScrollParent(Layer* parent);
185
186  Layer* scroll_parent() { return scroll_parent_; }
187  const Layer* scroll_parent() const { return scroll_parent_; }
188
189  void AddScrollChild(Layer* child);
190  void RemoveScrollChild(Layer* child);
191
192  std::set<Layer*>* scroll_children() { return scroll_children_.get(); }
193  const std::set<Layer*>* scroll_children() const {
194    return scroll_children_.get();
195  }
196
197  void SetClipParent(Layer* ancestor);
198
199  Layer* clip_parent() { return clip_parent_; }
200  const Layer* clip_parent() const {
201    return clip_parent_;
202  }
203
204  void AddClipChild(Layer* child);
205  void RemoveClipChild(Layer* child);
206
207  std::set<Layer*>* clip_children() { return clip_children_.get(); }
208  const std::set<Layer*>* clip_children() const {
209    return clip_children_.get();
210  }
211
212  DrawProperties<Layer>& draw_properties() { return draw_properties_; }
213  const DrawProperties<Layer>& draw_properties() const {
214    return draw_properties_;
215  }
216
217  // The following are shortcut accessors to get various information from
218  // draw_properties_
219  const gfx::Transform& draw_transform() const {
220    return draw_properties_.target_space_transform;
221  }
222  const gfx::Transform& screen_space_transform() const {
223    return draw_properties_.screen_space_transform;
224  }
225  float draw_opacity() const { return draw_properties_.opacity; }
226  bool draw_opacity_is_animating() const {
227    return draw_properties_.opacity_is_animating;
228  }
229  bool draw_transform_is_animating() const {
230    return draw_properties_.target_space_transform_is_animating;
231  }
232  bool screen_space_transform_is_animating() const {
233    return draw_properties_.screen_space_transform_is_animating;
234  }
235  bool screen_space_opacity_is_animating() const {
236    return draw_properties_.screen_space_opacity_is_animating;
237  }
238  bool can_use_lcd_text() const { return draw_properties_.can_use_lcd_text; }
239  bool is_clipped() const { return draw_properties_.is_clipped; }
240  gfx::Rect clip_rect() const { return draw_properties_.clip_rect; }
241  gfx::Rect drawable_content_rect() const {
242    return draw_properties_.drawable_content_rect;
243  }
244  gfx::Rect visible_content_rect() const {
245    return draw_properties_.visible_content_rect;
246  }
247  Layer* render_target() {
248    DCHECK(!draw_properties_.render_target ||
249           draw_properties_.render_target->render_surface());
250    return draw_properties_.render_target;
251  }
252  const Layer* render_target() const {
253    DCHECK(!draw_properties_.render_target ||
254           draw_properties_.render_target->render_surface());
255    return draw_properties_.render_target;
256  }
257  RenderSurface* render_surface() const {
258    return draw_properties_.render_surface.get();
259  }
260  int num_unclipped_descendants() const {
261    return draw_properties_.num_unclipped_descendants;
262  }
263
264  void SetScrollOffset(gfx::Vector2d scroll_offset);
265  gfx::Vector2d scroll_offset() const { return scroll_offset_; }
266  void SetScrollOffsetFromImplSide(const gfx::Vector2d& scroll_offset);
267
268  void SetScrollClipLayerId(int clip_layer_id);
269  bool scrollable() const { return scroll_clip_layer_id_ != INVALID_ID; }
270
271  void SetUserScrollable(bool horizontal, bool vertical);
272  bool user_scrollable_horizontal() const {
273    return user_scrollable_horizontal_;
274  }
275  bool user_scrollable_vertical() const { return user_scrollable_vertical_; }
276
277  void SetShouldScrollOnMainThread(bool should_scroll_on_main_thread);
278  bool should_scroll_on_main_thread() const {
279    return should_scroll_on_main_thread_;
280  }
281
282  void SetHaveWheelEventHandlers(bool have_wheel_event_handlers);
283  bool have_wheel_event_handlers() const { return have_wheel_event_handlers_; }
284
285  void SetHaveScrollEventHandlers(bool have_scroll_event_handlers);
286  bool have_scroll_event_handlers() const {
287    return have_scroll_event_handlers_;
288  }
289
290  void SetNonFastScrollableRegion(const Region& non_fast_scrollable_region);
291  const Region& non_fast_scrollable_region() const {
292    return non_fast_scrollable_region_;
293  }
294
295  void SetTouchEventHandlerRegion(const Region& touch_event_handler_region);
296  const Region& touch_event_handler_region() const {
297    return touch_event_handler_region_;
298  }
299
300  void set_did_scroll_callback(const base::Closure& callback) {
301    did_scroll_callback_ = callback;
302  }
303
304  void SetDrawCheckerboardForMissingTiles(bool checkerboard);
305  bool draw_checkerboard_for_missing_tiles() const {
306    return draw_checkerboard_for_missing_tiles_;
307  }
308
309  void SetForceRenderSurface(bool force_render_surface);
310  bool force_render_surface() const { return force_render_surface_; }
311
312  gfx::Vector2d ScrollDelta() const { return gfx::Vector2d(); }
313  gfx::Vector2dF TotalScrollOffset() const {
314    // Floating point to match the LayerImpl version.
315    return scroll_offset() + ScrollDelta();
316  }
317
318  void SetDoubleSided(bool double_sided);
319  bool double_sided() const { return double_sided_; }
320
321  void SetShouldFlattenTransform(bool flatten);
322  bool should_flatten_transform() const { return should_flatten_transform_; }
323
324  bool Is3dSorted() const { return sorting_context_id_ != 0; }
325
326  void set_use_parent_backface_visibility(bool use) {
327    use_parent_backface_visibility_ = use;
328  }
329  bool use_parent_backface_visibility() const {
330    return use_parent_backface_visibility_;
331  }
332
333  virtual void SetLayerTreeHost(LayerTreeHost* host);
334
335  virtual bool HasDelegatedContent() const;
336  bool HasContributingDelegatedRenderPasses() const { return false; }
337
338  void SetIsDrawable(bool is_drawable);
339
340  void SetHideLayerAndSubtree(bool hide);
341  bool hide_layer_and_subtree() const { return hide_layer_and_subtree_; }
342
343  void SetReplicaLayer(Layer* layer);
344  Layer* replica_layer() { return replica_layer_.get(); }
345  const Layer* replica_layer() const { return replica_layer_.get(); }
346
347  bool has_mask() const { return !!mask_layer_.get(); }
348  bool has_replica() const { return !!replica_layer_.get(); }
349  bool replica_has_mask() const {
350    return replica_layer_.get() &&
351           (mask_layer_.get() || replica_layer_->mask_layer_.get());
352  }
353
354  int NumDescendantsThatDrawContent() const;
355
356  // This is only virtual for tests.
357  // TODO(awoloszyn): Remove this once we no longer need it for tests
358  virtual bool DrawsContent() const;
359
360  // This methods typically need to be overwritten by derived classes.
361  virtual void SavePaintProperties();
362  // Returns true iff any resources were updated that need to be committed.
363  virtual bool Update(ResourceUpdateQueue* queue,
364                      const OcclusionTracker<Layer>* occlusion);
365  virtual bool NeedMoreUpdates();
366  virtual void SetIsMask(bool is_mask) {}
367  virtual void ReduceMemoryUsage() {}
368  virtual void OnOutputSurfaceCreated() {}
369  virtual bool IsSuitableForGpuRasterization() const;
370
371  virtual scoped_refptr<base::debug::ConvertableToTraceFormat> TakeDebugInfo();
372
373  void SetLayerClient(LayerClient* client) { client_ = client; }
374
375  virtual void PushPropertiesTo(LayerImpl* layer);
376
377  void CreateRenderSurface();
378  void ClearRenderSurface();
379  void ClearRenderSurfaceLayerList();
380
381  // The contents scale converts from logical, non-page-scaled pixels to target
382  // pixels. The contents scale is 1 for the root layer as it is already in
383  // physical pixels. By default contents scale is forced to be 1 except for
384  // subclasses of ContentsScalingLayer.
385  float contents_scale_x() const { return draw_properties_.contents_scale_x; }
386  float contents_scale_y() const { return draw_properties_.contents_scale_y; }
387  gfx::Size content_bounds() const { return draw_properties_.content_bounds; }
388
389  virtual void CalculateContentsScale(float ideal_contents_scale,
390                                      float* contents_scale_x,
391                                      float* contents_scale_y,
392                                      gfx::Size* content_bounds);
393
394  LayerTreeHost* layer_tree_host() { return layer_tree_host_; }
395  const LayerTreeHost* layer_tree_host() const { return layer_tree_host_; }
396
397  // Set the priority of all desired textures in this layer.
398  virtual void SetTexturePriorities(const PriorityCalculator& priority_calc) {}
399
400  bool AddAnimation(scoped_ptr<Animation> animation);
401  void PauseAnimation(int animation_id, double time_offset);
402  void RemoveAnimation(int animation_id);
403
404  LayerAnimationController* layer_animation_controller() {
405    return layer_animation_controller_.get();
406  }
407  void SetLayerAnimationControllerForTest(
408      scoped_refptr<LayerAnimationController> controller);
409
410  void set_layer_animation_delegate(AnimationDelegate* delegate) {
411    layer_animation_controller_->set_layer_animation_delegate(delegate);
412  }
413
414  bool HasActiveAnimation() const;
415
416  void AddLayerAnimationEventObserver(
417      LayerAnimationEventObserver* animation_observer);
418  void RemoveLayerAnimationEventObserver(
419      LayerAnimationEventObserver* animation_observer);
420
421  virtual SimpleEnclosedRegion VisibleContentOpaqueRegion() const;
422
423  virtual ScrollbarLayerInterface* ToScrollbarLayer();
424
425  gfx::Rect LayerRectToContentRect(const gfx::RectF& layer_rect) const;
426
427  virtual skia::RefPtr<SkPicture> GetPicture() const;
428
429  // Constructs a LayerImpl of the correct runtime type for this Layer type.
430  virtual scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl);
431
432  bool NeedsDisplayForTesting() const { return !update_rect_.IsEmpty(); }
433  void ResetNeedsDisplayForTesting() { update_rect_ = gfx::RectF(); }
434
435  RenderingStatsInstrumentation* rendering_stats_instrumentation() const;
436
437  const PaintProperties& paint_properties() const {
438    return paint_properties_;
439  }
440
441  // The scale at which contents should be rastered, to match the scale at
442  // which they will drawn to the screen. This scale is a component of the
443  // contents scale but does not include page/device scale factors.
444  // TODO(danakj): This goes away when TiledLayer goes away.
445  void set_raster_scale(float scale) { raster_scale_ = scale; }
446  float raster_scale() const { return raster_scale_; }
447  bool raster_scale_is_unknown() const { return raster_scale_ == 0.f; }
448
449  virtual bool SupportsLCDText() const;
450
451  void SetNeedsPushProperties();
452  bool needs_push_properties() const { return needs_push_properties_; }
453  bool descendant_needs_push_properties() const {
454    return num_dependents_need_push_properties_ > 0;
455  }
456  void reset_needs_push_properties_for_testing() {
457    needs_push_properties_ = false;
458  }
459
460  virtual void RunMicroBenchmark(MicroBenchmark* benchmark);
461
462  void Set3dSortingContextId(int id);
463  int sorting_context_id() const { return sorting_context_id_; }
464
465 protected:
466  friend class LayerImpl;
467  friend class TreeSynchronizer;
468  virtual ~Layer();
469
470  Layer();
471
472  // These SetNeeds functions are in order of severity of update:
473  //
474  // Called when this layer has been modified in some way, but isn't sure
475  // that it needs a commit yet.  It needs CalcDrawProperties and UpdateLayers
476  // before it knows whether or not a commit is required.
477  void SetNeedsUpdate();
478  // Called when a property has been modified in a way that the layer
479  // knows immediately that a commit is required.  This implies SetNeedsUpdate
480  // as well as SetNeedsPushProperties to push that property.
481  void SetNeedsCommit();
482  // Called when there's been a change in layer structure.  Implies both
483  // SetNeedsUpdate and SetNeedsCommit, but not SetNeedsPushProperties.
484  void SetNeedsFullTreeSync();
485
486  // Called when the next commit should wait until the pending tree is activated
487  // before finishing the commit and unblocking the main thread. Used to ensure
488  // unused resources on the impl thread are returned before commit completes.
489  void SetNextCommitWaitsForActivation();
490
491  // Will recalculate whether the layer draws content and set draws_content_
492  // appropriately.
493  void UpdateDrawsContent(bool has_drawable_content);
494  virtual bool HasDrawableContent() const;
495
496  // Called when the layer's number of drawable descendants changes.
497  void AddDrawableDescendants(int num);
498
499  void AddDependentNeedsPushProperties();
500  void RemoveDependentNeedsPushProperties();
501  bool parent_should_know_need_push_properties() const {
502    return needs_push_properties() || descendant_needs_push_properties();
503  }
504
505  bool IsPropertyChangeAllowed() const;
506
507  // If this layer has a scroll parent, it removes |this| from its list of
508  // scroll children.
509  void RemoveFromScrollTree();
510
511  // If this layer has a clip parent, it removes |this| from its list of clip
512  // children.
513  void RemoveFromClipTree();
514
515  void reset_raster_scale_to_unknown() { raster_scale_ = 0.f; }
516
517  // This flag is set when the layer needs to push properties to the impl
518  // side.
519  bool needs_push_properties_;
520
521  // The number of direct children or dependent layers that need to be recursed
522  // to in order for them or a descendent of them to push properties to the impl
523  // side.
524  int num_dependents_need_push_properties_;
525
526  // Tracks whether this layer may have changed stacking order with its
527  // siblings.
528  bool stacking_order_changed_;
529
530  // The update rect is the region of the compositor resource that was
531  // actually updated by the compositor. For layers that may do updating
532  // outside the compositor's control (i.e. plugin layers), this information
533  // is not available and the update rect will remain empty.
534  // Note this rect is in layer space (not content space).
535  gfx::RectF update_rect_;
536
537  scoped_refptr<Layer> mask_layer_;
538
539  int layer_id_;
540
541  // When true, the layer is about to perform an update. Any commit requests
542  // will be handled implicitly after the update completes.
543  bool ignore_set_needs_commit_;
544
545  // Layers that share a sorting context id will be sorted together in 3d
546  // space.  0 is a special value that means this layer will not be sorted and
547  // will be drawn in paint order.
548  int sorting_context_id_;
549
550 private:
551  friend class base::RefCounted<Layer>;
552
553  void SetParent(Layer* layer);
554  bool DescendantIsFixedToContainerLayer() const;
555
556  // Returns the index of the child or -1 if not found.
557  int IndexOfChild(const Layer* reference);
558
559  // This should only be called from RemoveFromParent().
560  void RemoveChildOrDependent(Layer* child);
561
562  // LayerAnimationValueProvider implementation.
563  virtual gfx::Vector2dF ScrollOffsetForAnimation() const OVERRIDE;
564
565  // LayerAnimationValueObserver implementation.
566  virtual void OnFilterAnimated(const FilterOperations& filters) OVERRIDE;
567  virtual void OnOpacityAnimated(float opacity) OVERRIDE;
568  virtual void OnTransformAnimated(const gfx::Transform& transform) OVERRIDE;
569  virtual void OnScrollOffsetAnimated(
570      const gfx::Vector2dF& scroll_offset) OVERRIDE;
571  virtual void OnAnimationWaitingForDeletion() OVERRIDE;
572  virtual bool IsActive() const OVERRIDE;
573
574  LayerList children_;
575  Layer* parent_;
576
577  // Layer instances have a weak pointer to their LayerTreeHost.
578  // This pointer value is nil when a Layer is not in a tree and is
579  // updated via SetLayerTreeHost() if a layer moves between trees.
580  LayerTreeHost* layer_tree_host_;
581
582  scoped_refptr<LayerAnimationController> layer_animation_controller_;
583
584  // Layer properties.
585  gfx::Size bounds_;
586
587  gfx::Vector2d scroll_offset_;
588  // This variable indicates which ancestor layer (if any) whose size,
589  // transformed relative to this layer, defines the maximum scroll offset for
590  // this layer.
591  int scroll_clip_layer_id_;
592  int num_descendants_that_draw_content_;
593  bool should_scroll_on_main_thread_ : 1;
594  bool have_wheel_event_handlers_ : 1;
595  bool have_scroll_event_handlers_ : 1;
596  bool user_scrollable_horizontal_ : 1;
597  bool user_scrollable_vertical_ : 1;
598  bool is_root_for_isolated_group_ : 1;
599  bool is_container_for_fixed_position_layers_ : 1;
600  bool is_drawable_ : 1;
601  bool draws_content_ : 1;
602  bool hide_layer_and_subtree_ : 1;
603  bool masks_to_bounds_ : 1;
604  bool contents_opaque_ : 1;
605  bool double_sided_ : 1;
606  bool should_flatten_transform_ : 1;
607  bool use_parent_backface_visibility_ : 1;
608  bool draw_checkerboard_for_missing_tiles_ : 1;
609  bool force_render_surface_ : 1;
610  bool transform_is_invertible_ : 1;
611  Region non_fast_scrollable_region_;
612  Region touch_event_handler_region_;
613  gfx::PointF position_;
614  SkColor background_color_;
615  float opacity_;
616  SkXfermode::Mode blend_mode_;
617  FilterOperations filters_;
618  FilterOperations background_filters_;
619  LayerPositionConstraint position_constraint_;
620  Layer* scroll_parent_;
621  scoped_ptr<std::set<Layer*> > scroll_children_;
622
623  Layer* clip_parent_;
624  scoped_ptr<std::set<Layer*> > clip_children_;
625
626  gfx::Transform transform_;
627  gfx::Point3F transform_origin_;
628
629  // Replica layer used for reflections.
630  scoped_refptr<Layer> replica_layer_;
631
632  // Transient properties.
633  float raster_scale_;
634
635  LayerClient* client_;
636
637  ScopedPtrVector<CopyOutputRequest> copy_requests_;
638
639  base::Closure did_scroll_callback_;
640
641  DrawProperties<Layer> draw_properties_;
642
643  PaintProperties paint_properties_;
644
645  DISALLOW_COPY_AND_ASSIGN(Layer);
646};
647
648}  // namespace cc
649
650#endif  // CC_LAYERS_LAYER_H_
651