cc: Support animating scroll offset

cc/layers/layer.h

 // Copyright 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_LAYERS_LAYER_H_
 #define CC_LAYERS_LAYER_H_
 
 #include <set>
 #include <string>
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "cc/animation/layer_animation_controller.h"
 #include "cc/animation/layer_animation_value_observer.h"
+#include "cc/animation/layer_animation_value_provider.h"
 #include "cc/base/cc_export.h"
 #include "cc/base/region.h"
 #include "cc/base/scoped_ptr_vector.h"
 #include "cc/debug/micro_benchmark.h"
 #include "cc/layers/compositing_reasons.h"
 #include "cc/layers/draw_properties.h"
 #include "cc/layers/layer_lists.h"
 #include "cc/layers/layer_position_constraint.h"
 #include "cc/layers/paint_properties.h"
 #include "cc/layers/render_surface.h"
@@ skipping 26 matching lines @@
 class LayerTreeImpl;
 class PriorityCalculator;
 class RenderingStatsInstrumentation;
 class ResourceUpdateQueue;
 class ScrollbarLayerInterface;
 struct AnimationEvent;
 
 // Base class for composited layers. Special layer types are derived from
 // this class.
 class CC_EXPORT Layer : public base::RefCounted<Layer>,
-                        public LayerAnimationValueObserver {
+                        public LayerAnimationValueObserver,
+                        public LayerAnimationValueProvider {
  public:
   typedef RenderSurfaceLayerList RenderSurfaceListType;
   typedef LayerList LayerListType;
   typedef RenderSurface RenderSurfaceType;
 
   enum LayerIdLabels {
     INVALID_ID = -1,
   };
 
   static scoped_refptr<Layer> Create();
@@ skipping 458 matching lines @@
 
   void SetParent(Layer* layer);
   bool DescendantIsFixedToContainerLayer() const;
 
   // Returns the index of the child or -1 if not found.
   int IndexOfChild(const Layer* reference);
 
   // This should only be called from RemoveFromParent().
   void RemoveChildOrDependent(Layer* child);
 
+  // LayerAnimationValueProvider implementation.
+  virtual gfx::Vector2dF ScrollOffsetForAnimation() const OVERRIDE;
+
   // LayerAnimationValueObserver implementation.
   virtual void OnFilterAnimated(const FilterOperations& filters) OVERRIDE;
   virtual void OnOpacityAnimated(float opacity) OVERRIDE;
   virtual void OnTransformAnimated(const gfx::Transform& transform) OVERRIDE;
+  virtual void OnScrollOffsetAnimated(gfx::Vector2dF scroll_offset) OVERRIDE;
   virtual void OnAnimationWaitingForDeletion() OVERRIDE;
   virtual bool IsActive() const OVERRIDE;
 
   LayerList children_;
   Layer* parent_;
 
   // Layer instances have a weak pointer to their LayerTreeHost.
   // This pointer value is nil when a Layer is not in a tree and is
   // updated via SetLayerTreeHost() if a layer moves between trees.
   LayerTreeHost* layer_tree_host_;
@@ skipping 57 matching lines @@
   DrawProperties<Layer> draw_properties_;
 
   PaintProperties paint_properties_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_H_