Early terminate flings when scrolling impossible

cc/trees/layer_tree_host_impl.h

 // Copyright 2011 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_TREES_LAYER_TREE_HOST_IMPL_H_
 #define CC_TREES_LAYER_TREE_HOST_IMPL_H_
 
 #include <list>
 #include <set>
 #include <string>
@@ skipping 105 matching lines @@
       InputHandler::ScrollInputType type) OVERRIDE;
   virtual bool ScrollBy(const gfx::Point& viewport_point,
                         const gfx::Vector2dF& scroll_delta) OVERRIDE;
   virtual bool ScrollVerticallyByPage(const gfx::Point& viewport_point,
                                       ScrollDirection direction) OVERRIDE;
   virtual void SetRootLayerScrollOffsetDelegate(
       LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate) OVERRIDE;
   virtual void OnRootLayerDelegatedScrollOffsetChanged() OVERRIDE;
   virtual void ScrollEnd() OVERRIDE;
   virtual InputHandler::ScrollStatus FlingScrollBegin() OVERRIDE;
-  virtual void NotifyCurrentFlingVelocity(
-      const gfx::Vector2dF& velocity) OVERRIDE;
   virtual void MouseMoveAt(const gfx::Point& viewport_point) OVERRIDE;
   virtual void PinchGestureBegin() OVERRIDE;
   virtual void PinchGestureUpdate(float magnify_delta,
                                   const gfx::Point& anchor) OVERRIDE;
   virtual void PinchGestureEnd() OVERRIDE;
   virtual void StartPageScaleAnimation(const gfx::Vector2d& target_offset,
                                        bool anchor_point,
                                        float page_scale,
                                        base::TimeDelta duration) OVERRIDE;
   virtual void ScheduleAnimation() OVERRIDE;
@@ skipping 238 matching lines @@
     }
     size_t RenderPassListNext(size_t it) const { return it + 1; }
   };
 
   template <typename RenderPassCuller>
       static void RemoveRenderPasses(RenderPassCuller culler, FrameData* frame);
 
   gfx::Vector2dF accumulated_root_overscroll() const {
     return accumulated_root_overscroll_;
   }
-  gfx::Vector2dF current_fling_velocity() const {
-    return current_fling_velocity_;
-  }
 
   bool pinch_gesture_active() const { return pinch_gesture_active_; }
 
   void SetTreePriority(TreePriority priority);
 
   void UpdateCurrentFrameTime();
   void ResetCurrentFrameTimeForNextFrame();
   virtual base::TimeTicks CurrentFrameTimeTicks();
 
   scoped_ptr<base::Value> AsValue() const { return AsValueWithFrame(NULL); }
@@ skipping 168 matching lines @@
   bool tile_priorities_dirty_;
 
   // The optional delegate for the root layer scroll offset.
   LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate_;
   LayerTreeSettings settings_;
   LayerTreeDebugState debug_state_;
   bool visible_;
   ManagedMemoryPolicy cached_managed_memory_policy_;
 
   gfx::Vector2dF accumulated_root_overscroll_;
-  gfx::Vector2dF current_fling_velocity_;
 
   bool pinch_gesture_active_;
   bool pinch_gesture_end_should_clear_scrolling_layer_;
   gfx::Point previous_pinch_anchor_;
 
   scoped_ptr<TopControlsManager> top_controls_manager_;
 
   scoped_ptr<PageScaleAnimation> page_scale_animation_;
 
   // This is used for ticking animations slowly when hidden.
@@ skipping 70 matching lines @@
   int id_;
 
   std::set<SwapPromiseMonitor*> swap_promise_monitor_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_IMPL_H_