cc: Change preraster/predecode split to be half of max skewport extent.

cc/tiles/picture_layer_tiling_set.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_TILES_PICTURE_LAYER_TILING_SET_H_
 #define CC_TILES_PICTURE_LAYER_TILING_SET_H_
 
 #include <stddef.h>
 
 #include <set>
@@ skipping 26 matching lines @@
 
     size_t start;
     size_t end;
   };
 
   static std::unique_ptr<PictureLayerTilingSet> Create(
       WhichTree tree,
       PictureLayerTilingClient* client,
       int tiling_interest_area_padding,
       float skewport_target_time_in_seconds,
-      int skewport_extrapolation_limit_in_screen_pixels);
+      int skewport_extrapolation_limit_in_screen_pixels,
+      float max_preraster_distance);
 
   ~PictureLayerTilingSet();
 
   const PictureLayerTilingClient* client() const { return client_; }
 
   void CleanUpTilings(float min_acceptable_high_res_scale,
                       float max_acceptable_high_res_scale,
                       const std::vector<PictureLayerTiling*>& needed_tilings,
                       PictureLayerTilingSet* twin_set);
   void RemoveNonIdealTilings();
@@ skipping 141 matching lines @@
 
     bool invalidated;
     bool added_tilings;
   };
 
   explicit PictureLayerTilingSet(
       WhichTree tree,
       PictureLayerTilingClient* client,
       int tiling_interest_area_padding,
       float skewport_target_time_in_seconds,
-      int skewport_extrapolation_limit_in_screen_pixels);
+      int skewport_extrapolation_limit_in_screen_pixels,
+      float max_preraster_distance);
 
   void CopyTilingsAndPropertiesFromPendingTwin(
       const PictureLayerTilingSet* pending_twin_set,
       scoped_refptr<RasterSource> raster_source,
       const Region& layer_invalidation);
 
   // Remove one tiling.
   void Remove(PictureLayerTiling* tiling);
   void VerifyTilings(const PictureLayerTilingSet* pending_twin_set) const;
 
   bool TilingsNeedUpdate(const gfx::Rect& required_rect_in_layer_space,
                          double current_frame_time_in_Seconds);
   gfx::Rect ComputeSkewport(const gfx::Rect& visible_rect_in_layer_space,
                             double current_frame_time_in_seconds,
                             float ideal_contents_scale);
   gfx::Rect ComputeSoonBorderRect(const gfx::Rect& visible_rect_in_layer_space,
                                   float ideal_contents_scale);
   void UpdatePriorityRects(const gfx::Rect& visible_rect_in_layer_space,
                            double current_frame_time_in_seconds,
                            float ideal_contents_scale);
 
   std::vector<std::unique_ptr<PictureLayerTiling>> tilings_;
 
   const int tiling_interest_area_padding_;
   const float skewport_target_time_in_seconds_;
   const int skewport_extrapolation_limit_in_screen_pixels_;
   WhichTree tree_;
   PictureLayerTilingClient* client_;
+  const float max_preraster_distance_;
   // State saved for computing velocities based on finite differences.
   // .front() of the list refers to the most recent FrameVisibleRect.
   std::list<FrameVisibleRect> visible_rect_history_;
   StateSinceLastTilePriorityUpdate state_since_last_tile_priority_update_;
 
   scoped_refptr<RasterSource> raster_source_;
 
   gfx::Rect visible_rect_in_layer_space_;
   gfx::Rect skewport_in_layer_space_;
   gfx::Rect soon_border_rect_in_layer_space_;
   gfx::Rect eventually_rect_in_layer_space_;
 
   friend class Iterator;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PictureLayerTilingSet);
 };
 
 }  // namespace cc
 
 #endif  // CC_TILES_PICTURE_LAYER_TILING_SET_H_