cc: Make tiling interest rect calc based on viewport.

cc/resources/picture_layer_tiling_set.h

Index: cc/resources/picture_layer_tiling_set.h
diff --git a/cc/resources/picture_layer_tiling_set.h b/cc/resources/picture_layer_tiling_set.h
index e51d7ecd8bacff21eb43ffcb1d3a3f1f9ad59af2..a51f07ee560e934d0d191bebf5a6b11b332ed57a 100644
--- a/cc/resources/picture_layer_tiling_set.h
+++ b/cc/resources/picture_layer_tiling_set.h
@@ -40,7 +40,7 @@ class CC_EXPORT PictureLayerTilingSet {
   static scoped_ptr<PictureLayerTilingSet> Create(
       WhichTree tree,
       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);
 
@@ -176,7 +176,7 @@ class CC_EXPORT PictureLayerTilingSet {
   explicit PictureLayerTilingSet(
       WhichTree tree,
       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);
 
@@ -191,7 +191,7 @@ class CC_EXPORT PictureLayerTilingSet {
 
   ScopedPtrVector<PictureLayerTiling> tilings_;
 
-  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_;
   WhichTree tree_;