cc: Remove separate x/y raster scales.

cc/tiles/tile.h

Index: cc/tiles/tile.h
diff --git a/cc/tiles/tile.h b/cc/tiles/tile.h
index 1bce3cd3603e9288b113ac54abaf07c93fffae91..16d37d1491d88a5f9b7938eada47ed21ea32d2d2 100644
--- a/cc/tiles/tile.h
+++ b/cc/tiles/tile.h
@@ -29,20 +29,20 @@ class CC_EXPORT Tile {
     int tiling_j_index;
     gfx::Rect enclosing_layer_rect;
     gfx::Rect content_rect;
-    gfx::SizeF raster_scales;
+    float contents_scale;
 
     CreateInfo(const PictureLayerTiling* tiling,
                int tiling_i_index,
                int tiling_j_index,
                const gfx::Rect& enclosing_layer_rect,
                const gfx::Rect& content_rect,
-               const gfx::SizeF& raster_scales)
+               float contents_scale)
         : tiling(tiling),
           tiling_i_index(tiling_i_index),
           tiling_j_index(tiling_j_index),
           enclosing_layer_rect(enclosing_layer_rect),
           content_rect(content_rect),
-          raster_scales(raster_scales) {}
+          contents_scale(contents_scale) {}
   };
 
   enum TileRasterFlags { USE_PICTURE_ANALYSIS = 1 << 0, IS_OPAQUE = 1 << 1 };
@@ -76,8 +76,7 @@ class CC_EXPORT Tile {
   const TileDrawInfo& draw_info() const { return draw_info_; }
   TileDrawInfo& draw_info() { return draw_info_; }
 
-  float contents_scale_key() const { return raster_scales_.width(); }
-  const gfx::SizeF& raster_scales() const { return raster_scales_; }
+  float contents_scale() const { return contents_scale_; }
   const gfx::Rect& content_rect() const { return content_rect_; }
   const gfx::Rect& enclosing_layer_rect() const {
     return enclosing_layer_rect_;
@@ -133,7 +132,7 @@ class CC_EXPORT Tile {
   const PictureLayerTiling* tiling_;
   const gfx::Rect content_rect_;
   const gfx::Rect enclosing_layer_rect_;
-  const gfx::SizeF raster_scales_;
+  const float contents_scale_;
 
   TileDrawInfo draw_info_;