cc: Make tiling interest rect calc based on viewport.

cc/resources/picture_layer_tiling.cc

Index: cc/resources/picture_layer_tiling.cc
diff --git a/cc/resources/picture_layer_tiling.cc b/cc/resources/picture_layer_tiling.cc
index 21c1417e5b4fd891e7e16df8dd23fa87ed63fdda..aa6fad4501a5320b4cffaf6ec72ca54634f4582b 100644
--- a/cc/resources/picture_layer_tiling.cc
+++ b/cc/resources/picture_layer_tiling.cc
@@ -33,12 +33,12 @@ scoped_ptr<PictureLayerTiling> PictureLayerTiling::Create(
     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) {
   return make_scoped_ptr(new PictureLayerTiling(
-      tree, contents_scale, raster_source, client, max_tiles_for_interest_area,
-      skewport_target_time_in_seconds,
+      tree, contents_scale, raster_source, client,
+      tiling_interest_area_viewport_multiplier, skewport_target_time_in_seconds,
       skewport_extrapolation_limit_in_content_pixels));
 }
 
@@ -47,10 +47,11 @@ PictureLayerTiling::PictureLayerTiling(
     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)
-    : max_tiles_for_interest_area_(max_tiles_for_interest_area),
+    : tiling_interest_area_viewport_multiplier_(
+          tiling_interest_area_viewport_multiplier),
       skewport_target_time_in_seconds_(skewport_target_time_in_seconds),
       skewport_extrapolation_limit_in_content_pixels_(
           skewport_extrapolation_limit_in_content_pixels),
@@ -575,7 +576,6 @@ bool PictureLayerTiling::ComputeTilePriorityRects(
     DCHECK_NE(current_frame_time_in_seconds, 0.0);
     return false;
   }
-
   gfx::Rect visible_rect_in_content_space =
       gfx::ScaleToEnclosingRect(viewport_in_layer_space, contents_scale_);
 
@@ -592,9 +592,9 @@ bool PictureLayerTiling::ComputeTilePriorityRects(
   DCHECK(skewport.Contains(visible_rect_in_content_space));
 
   // Calculate the eventually/live tiles rect.
-  gfx::Size tile_size = tiling_data_.max_texture_size();
-  int64 eventually_rect_area =
-      max_tiles_for_interest_area_ * tile_size.width() * tile_size.height();
+  int64 eventually_rect_area = tiling_interest_area_viewport_multiplier_ *
+                               visible_rect_in_content_space.width() *
+                               visible_rect_in_content_space.height();
 
   gfx::Rect eventually_rect =
       ExpandRectEquallyToAreaBoundedBy(visible_rect_in_content_space,