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

cc/resources/picture_layer_tiling.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_RESOURCES_PICTURE_LAYER_TILING_H_
 #define CC_RESOURCES_PICTURE_LAYER_TILING_H_
 
 #include <set>
 #include <utility>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/containers/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
 #include "cc/base/cc_export.h"
 #include "cc/base/region.h"
 #include "cc/base/tiling_data.h"
 #include "cc/resources/tile.h"
 #include "cc/resources/tile_priority.h"
+#include "cc/trees/occlusion.h"
 #include "ui/gfx/rect.h"
 
 namespace base {
 namespace debug {
 class TracedValue;
 }
 }
 
 namespace cc {
 
-template <typename LayerType>
-class OcclusionTracker;
 class PictureLayerTiling;
 class PicturePileImpl;
 
 class CC_EXPORT PictureLayerTilingClient {
  public:
   // Create a tile at the given content_rect (in the contents scale of the
   // tiling) This might return null if the client cannot create such a tile.
   virtual scoped_refptr<Tile> CreateTile(
     PictureLayerTiling* tiling,
     const gfx::Rect& content_rect) = 0;
@@ skipping 188 matching lines @@
     int left_;
     int top_;
     int right_;
     int bottom_;
 
     friend class PictureLayerTiling;
   };
 
   void Reset();
 
-  void UpdateTilePriorities(
-      WhichTree tree,
-      const gfx::Rect& visible_layer_rect,
-      float ideal_contents_scale,
-      double current_frame_time_in_seconds,
-      const OcclusionTracker<LayerImpl>* occlusion_tracker,
-      const LayerImpl* render_target,
-      const gfx::Transform& draw_transform);
+  void UpdateTilePriorities(WhichTree tree,
+                            const gfx::Rect& visible_layer_rect,
+                            float ideal_contents_scale,
+                            double current_frame_time_in_seconds,
+                            const Occlusion& occlusion_in_layer_space);
 
   // Copies the src_tree priority into the dst_tree priority for all tiles.
   // The src_tree priority is reset to the lowest priority possible.  This
   // also updates the pile on each tile to be the current client's pile.
   void DidBecomeActive();
 
   // Resets the active priority for all tiles in a tiling, when an active
   // tiling is becoming recycled. This may include some tiles which are
   // not in the the pending tiling (due to invalidations). This must
   // be called before DidBecomeActive, as it resets the active priority
@@ skipping 103 matching lines @@
 
  private:
   DISALLOW_ASSIGN(PictureLayerTiling);
 
   RectExpansionCache expansion_cache_;
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_PICTURE_LAYER_TILING_H_