cc: Remove the base RasterSource

cc/test/fake_picture_layer_tiling_client.h

Index: cc/test/fake_picture_layer_tiling_client.h
diff --git a/cc/test/fake_picture_layer_tiling_client.h b/cc/test/fake_picture_layer_tiling_client.h
index bce66489aa3b8373d2925cff388ea7a213afc032..735227695b28a0f00d46ebdd9dd8e1ada0605bad 100644
--- a/cc/test/fake_picture_layer_tiling_client.h
+++ b/cc/test/fake_picture_layer_tiling_client.h
@@ -46,7 +46,7 @@ class FakePictureLayerTilingClient : public PictureLayerTilingClient {
   void set_has_valid_tile_priorities(bool has_valid_tile_priorities) {
     has_valid_tile_priorities_ = has_valid_tile_priorities;
   }
-  RasterSource* raster_source() { return raster_source_.get(); }
+  DisplayListRasterSource* raster_source() { return raster_source_.get(); }
 
   TileManager* tile_manager() const {
     return tile_manager_.get();