Remaining code for basic tile compression functionality.

cc/tiles/tile.h

Index: cc/tiles/tile.h
diff --git a/cc/tiles/tile.h b/cc/tiles/tile.h
index e53c2ac52f808a23e5658b476eca2244b3e6f005..7678d69a034123532ba84e51192646cf53d5b97c 100644
--- a/cc/tiles/tile.h
+++ b/cc/tiles/tile.h
@@ -23,7 +23,7 @@ class CC_EXPORT Tile {
     void operator()(Tile* tile) const;
   };
 
-  enum TileRasterFlags { USE_PICTURE_ANALYSIS = 1 << 0 };
+  enum TileRasterFlags { USE_PICTURE_ANALYSIS = 1 << 0, IS_OPAQUE = 1 << 1 };
 
   typedef uint64 Id;
 
@@ -45,6 +45,8 @@ class CC_EXPORT Tile {
     return !!(flags_ & USE_PICTURE_ANALYSIS);
   }
 
+  bool is_opaque() const { return !!(flags_ & IS_OPAQUE); }
+
   void AsValueInto(base::trace_event::TracedValue* value) const;
 
   const TileDrawInfo& draw_info() const { return draw_info_; }