cc: Split tiling set raster queues into all and required.

cc/resources/picture_layer_tiling.h

Index: cc/resources/picture_layer_tiling.h
diff --git a/cc/resources/picture_layer_tiling.h b/cc/resources/picture_layer_tiling.h
index a5a4efa33dc2768c19c5975167d7a4f458de8177..cf5e795aecc4d1055aeaac99164b3237f4ca5a54 100644
--- a/cc/resources/picture_layer_tiling.h
+++ b/cc/resources/picture_layer_tiling.h
@@ -58,6 +58,8 @@ class CC_EXPORT PictureLayerTiling {
  public:
   static const int kBorderTexels = 1;
 
+  // TODO(vmpstr): Move this to a separate file.
+  // TODO(vmpstr): Take a bool indicating that we only need required tiles.
   class CC_EXPORT TilingRasterTileIterator {
    public:
     TilingRasterTileIterator();