[cc]: Add a BeginMainFrameNotExpectedSoon signal and route it to the RendererScheduler.

cc/trees/single_thread_proxy.cc

Index: cc/trees/single_thread_proxy.cc
diff --git a/cc/trees/single_thread_proxy.cc b/cc/trees/single_thread_proxy.cc
index dc58d39a0911e9561feb942e27c0bd168e9a568d..2805c6db1983dbecec8afc019c37130a08d400cb 100644
--- a/cc/trees/single_thread_proxy.cc
+++ b/cc/trees/single_thread_proxy.cc
@@ -674,6 +674,10 @@ void SingleThreadProxy::ScheduledActionSendBeginMainFrame() {
                  weak_factory_.GetWeakPtr()));
 }
 
+void SingleThreadProxy::SendBeginMainFrameNoLongerRequired() {
+  layer_tree_host_->BeginMainFrameNoLongerRequired();
+}
+
 void SingleThreadProxy::BeginMainFrame() {
   if (defer_commits_) {
     TRACE_EVENT_INSTANT0("cc", "EarlyOut_DeferCommit",