cc: Check for completed raster tasks at interval.

cc/layer_tree_host_impl.h

Index: cc/layer_tree_host_impl.h
diff --git a/cc/layer_tree_host_impl.h b/cc/layer_tree_host_impl.h
index 0d51dbfbf5b8ab31bde76ee9fa8cc6c87294da71..d96823f8e0e3ef4ef6e5fc16658615bb276affa4 100644
--- a/cc/layer_tree_host_impl.h
+++ b/cc/layer_tree_host_impl.h
@@ -53,6 +53,7 @@ public:
     virtual void didUploadVisibleHighResolutionTileOnImplThread() = 0;
     virtual void setNeedsCommitOnImplThread() = 0;
     virtual void setNeedsManageTilesOnImplThread() = 0;
+    virtual void setNeedsCheckForCompletedRasterTasksOnImplThread() = 0;
     virtual void postAnimationEventsToMainThreadOnImplThread(scoped_ptr<AnimationEventsVector>, base::Time wallClockTime) = 0;
     // Returns true if resources were deleted by this call.
     virtual bool reduceContentsTextureMemoryOnImplThread(size_t limitBytes, int priorityCutoff) = 0;
@@ -137,6 +138,7 @@ public:
 
     // TileManagerClient implementation.
     virtual void ScheduleManageTiles() OVERRIDE;
+    virtual void ScheduleCheckForCompletedRasterTasks() OVERRIDE;
     virtual void DidUploadVisibleHighResolutionTile() OVERRIDE;
 
     // OutputSurfaceClient implementation.
@@ -260,6 +262,8 @@ public:
     void beginNextFrame();
     base::TimeTicks currentFrameTime();
 
+    void checkForCompletedRasterTasks();
+
 protected:
     LayerTreeHostImpl(const LayerTreeSettings&, LayerTreeHostImplClient*, Proxy*);
     void activatePendingTree();