cc: Throttle tile priority updates to once a frame.

cc/layer_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_LAYER_IMPL_H_
 #define CC_LAYER_IMPL_H_
 
 #include <string>
 
 #include "base/logging.h"
@@ skipping 89 matching lines @@
     virtual void appendQuads(QuadSink&, AppendQuadsData&) { }
     virtual void didDraw(ResourceProvider*);
 
     virtual ResourceProvider::ResourceId contentsResourceId() const;
 
     virtual bool hasDelegatedContent() const;
     virtual bool hasContributingDelegatedRenderPasses() const;
     virtual RenderPass::Id firstContributingRenderPassId() const;
     virtual RenderPass::Id nextContributingRenderPassId(RenderPass::Id) const;
 
+    virtual void updateTilePriorities() { }
+
     virtual ScrollbarLayerImpl* toScrollbarLayer();
 
     // Returns true if this layer has content to draw.
     void setDrawsContent(bool);
     bool drawsContent() const { return m_drawsContent; }
 
     bool forceRenderSurface() const { return m_forceRenderSurface; }
     void setForceRenderSurface(bool force) { m_forceRenderSurface = force; }
 
     void setAnchorPoint(const gfx::PointF&);
@@ skipping 151 matching lines @@
     bool layerSurfacePropertyChanged() const;
 
     void resetAllChangeTrackingForSubtree();
 
     virtual bool layerIsAlwaysDamaged() const;
 
     LayerAnimationController* layerAnimationController() { return m_layerAnimationController.get(); }
 
     virtual Region visibleContentOpaqueRegion() const;
 
-    virtual void didUpdateTransforms() { }
     virtual void didBecomeActive();
 
     // Indicates that the surface previously used to render this layer
     // was lost and that a new one has been created. Won't be called
     // until the new surface has been created successfully.
     virtual void didLoseOutputSurface();
 
     ScrollbarAnimationController* scrollbarAnimationController() const { return m_scrollbarAnimationController.get(); }
 
     void setScrollbarOpacity(float opacity);
@@ skipping 134 matching lines @@
     // Group of properties that need to be computed based on the layer tree
     // hierarchy before layers can be drawn.
     DrawProperties<LayerImpl, RenderSurfaceImpl> m_drawProperties;
 
     DISALLOW_COPY_AND_ASSIGN(LayerImpl);
 };
 
 }
 
 #endif  // CC_LAYER_IMPL_H_