cc: Split RasterTilePriorityQueue into required and all based on type.

cc/resources/tiling_set_raster_queue.h

Index: cc/resources/tiling_set_raster_queue.h
diff --git a/cc/resources/tiling_set_raster_queue.h b/cc/resources/tiling_set_raster_queue.h
index 0a131a99bb9492217f24c0a763ff6e4824495674..7a238d6cc3508e7cb9dd7f2c7bc6d0728d8ed8e5 100644
--- a/cc/resources/tiling_set_raster_queue.h
+++ b/cc/resources/tiling_set_raster_queue.h
@@ -8,6 +8,8 @@
 namespace cc {
 class Tile;
 
+// TODO(vmpstr): Remove this, since RasterTilePriorityQueue knows the type
+// directly.
 class TilingSetRasterQueue {
  public:
   virtual ~TilingSetRasterQueue() {}