cc: Make tiling interest rect calc based on viewport.

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 <map>
 #include <utility>
 #include <vector>
@@ skipping 50 matching lines @@
   static float CalculateSoonBorderDistance(
       const gfx::Rect& visible_rect_in_content_space,
       float content_to_screen_scale);
 
   // Create a tiling with no tiles. CreateTile() must be called to add some.
   static scoped_ptr<PictureLayerTiling> Create(
       WhichTree tree,
       float contents_scale,
       scoped_refptr<RasterSource> raster_source,
       PictureLayerTilingClient* client,
-      size_t max_tiles_for_interest_area,
+      float tiling_interest_area_viewport_multiplier,
       float skewport_target_time_in_seconds,
       int skewport_extrapolation_limit_in_content_pixels);
 
   void SetRasterSourceAndResize(scoped_refptr<RasterSource> raster_source);
   void Invalidate(const Region& layer_invalidation);
   void SetRasterSourceOnTiles();
   void CreateMissingTilesInLiveTilesRect();
   void TakeTilesAndPropertiesFrom(PictureLayerTiling* pending_twin,
                                   const Region& layer_invalidation);
 
@@ skipping 132 matching lines @@
 
   struct FrameVisibleRect {
     gfx::Rect visible_rect_in_content_space;
     double frame_time_in_seconds = 0.0;
   };
 
   PictureLayerTiling(WhichTree tree,
                      float contents_scale,
                      scoped_refptr<RasterSource> raster_source,
                      PictureLayerTilingClient* client,
-                     size_t max_tiles_for_interest_area,
+                     float tiling_interest_area_viewport_multiplier,
                      float skewport_target_time_in_seconds,
                      int skewport_extrapolation_limit_in_content_pixels);
   void SetLiveTilesRect(const gfx::Rect& live_tiles_rect);
   void VerifyLiveTilesRect(bool is_on_recycle_tree) const;
   Tile* CreateTile(int i, int j);
   // Returns true if the Tile existed and was removed from the tiling.
   bool RemoveTileAt(int i, int j);
   bool TilingMatchesTileIndices(const PictureLayerTiling* twin) const;
 
   // Computes a skewport. The calculation extrapolates the last visible
@@ skipping 60 matching lines @@
     return current_soon_border_rect_;
   }
   const gfx::Rect& current_eventually_rect() const {
     return current_eventually_rect_;
   }
   bool has_ever_been_updated() const {
     return visible_rect_history_[0].frame_time_in_seconds != 0.0;
   }
   void RemoveTilesInRegion(const Region& layer_region, bool recreate_tiles);
 
-  const size_t max_tiles_for_interest_area_;
+  const float tiling_interest_area_viewport_multiplier_;
   const float skewport_target_time_in_seconds_;
   const int skewport_extrapolation_limit_in_content_pixels_;
 
   // Given properties.
   const float contents_scale_;
   PictureLayerTilingClient* const client_;
   const WhichTree tree_;
   scoped_refptr<RasterSource> raster_source_;
   TileResolution resolution_;
 
@@ skipping 24 matching lines @@
 
  private:
   DISALLOW_ASSIGN(PictureLayerTiling);
 
   RectExpansionCache expansion_cache_;
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_PICTURE_LAYER_TILING_H_