Revert of Remove default begin frame sources from the renderer

cc/trees/layer_tree_host_impl_unittest.cc

Index: cc/trees/layer_tree_host_impl_unittest.cc
diff --git a/cc/trees/layer_tree_host_impl_unittest.cc b/cc/trees/layer_tree_host_impl_unittest.cc
index 96f999ea0aaf7a83b236536db05d5f3542a71f83..49aa90653ff7ea0ade4100c705b0cd741271b04e 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -131,6 +131,8 @@
   }
 
   void DidLoseOutputSurfaceOnImplThread() override {}
+  void CommitVSyncParameters(base::TimeTicks timebase,
+                             base::TimeDelta interval) override {}
   void SetBeginFrameSource(BeginFrameSource* source) override {}
   void SetEstimatedParentDrawTime(base::TimeDelta draw_time) override {}
   void DidSwapBuffersCompleteOnImplThread() override {}