Reland of: cc: Add occlusion checker as a fixed view of occlusion tracker.

cc/layers/picture_layer_impl.h

 // Copyright 2012 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_PICTURE_LAYER_IMPL_H_
 #define CC_LAYERS_PICTURE_LAYER_IMPL_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 92 matching lines @@
 
   // LayerImpl overrides.
   virtual const char* LayerTypeAsString() const OVERRIDE;
   virtual scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl)
       OVERRIDE;
   virtual void PushPropertiesTo(LayerImpl* layer) OVERRIDE;
   virtual void AppendQuads(RenderPass* render_pass,
                            const OcclusionTracker<LayerImpl>& occlusion_tracker,
                            AppendQuadsData* append_quads_data) OVERRIDE;
   virtual void UpdateTiles(
-      const OcclusionTracker<LayerImpl>* occlusion_tracker) OVERRIDE;
+      const Occlusion& occlusion_in_content_space) OVERRIDE;
   virtual void NotifyTileStateChanged(const Tile* tile) OVERRIDE;
   virtual void DidBecomeActive() OVERRIDE;
   virtual void DidBeginTracing() OVERRIDE;
   virtual void ReleaseResources() OVERRIDE;
   virtual skia::RefPtr<SkPicture> GetPicture() OVERRIDE;
 
   // PictureLayerTilingClient overrides.
   virtual scoped_refptr<Tile> CreateTile(
     PictureLayerTiling* tiling,
     const gfx::Rect& content_rect) OVERRIDE;
@@ skipping 29 matching lines @@
 
  protected:
   friend class LayerRasterTileIterator;
 
   PictureLayerImpl(LayerTreeImpl* tree_impl, int id);
   PictureLayerTiling* AddTiling(float contents_scale);
   void RemoveTiling(float contents_scale);
   void RemoveAllTilings();
   void SyncFromActiveLayer(const PictureLayerImpl* other);
   void AddTilingsForRasterScale();
-  void UpdateTilePriorities(
-      const OcclusionTracker<LayerImpl>* occlusion_tracker);
+  void UpdateTilePriorities(const Occlusion& occlusion_in_content_space);
   virtual bool ShouldAdjustRasterScale() const;
   virtual void RecalculateRasterScales();
   void CleanUpTilingsOnActiveLayer(
       std::vector<PictureLayerTiling*> used_tilings);
   float MinimumContentsScale() const;
   float SnappedContentsScale(float new_contents_scale);
   void ResetRasterScale();
   void MarkVisibleResourcesAsRequired() const;
   bool MarkVisibleTilesAsRequired(
       PictureLayerTiling* tiling,
@@ skipping 55 matching lines @@
   gfx::Rect viewport_rect_for_tile_priority_;
   gfx::Transform screen_space_transform_for_tile_priority_;
 
   friend class PictureLayer;
   DISALLOW_COPY_AND_ASSIGN(PictureLayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_PICTURE_LAYER_IMPL_H_