Make SingleThreadProxy a SchedulerClient

cc/trees/layer_tree_host_single_thread_client.h

Index: cc/trees/layer_tree_host_single_thread_client.h
diff --git a/cc/trees/layer_tree_host_single_thread_client.h b/cc/trees/layer_tree_host_single_thread_client.h
index cb6145048e66aac79f4cf8eeb81ad88dc90ed66a..827f70e688a48a3358c1ae0471eb8a3fe4b4cab2 100644
--- a/cc/trees/layer_tree_host_single_thread_client.h
+++ b/cc/trees/layer_tree_host_single_thread_client.h
@@ -9,12 +9,6 @@ namespace cc {
 
 class LayerTreeHostSingleThreadClient {
  public:
-  // Request that the client schedule a composite.
-  virtual void ScheduleComposite() = 0;
-  // Request that the client schedule a composite now, and calculate appropriate
-  // delay for potential future frame.
-  virtual void ScheduleAnimation() = 0;
-
   // Called whenever the compositor posts a SwapBuffers (either full or
   // partial). After DidPostSwapBuffers(), exactly one of
   // DidCompleteSwapBuffers() or DidAbortSwapBuffers() will be called, thus