cc: Add scheduler support for invalidating content on impl thread.

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 7aa7cfc0ce644be1826bfd7237837117740f73a2..7559ded9d445159876293711cf49c01da1b087a5 100644
--- a/cc/trees/single_thread_proxy.cc
+++ b/cc/trees/single_thread_proxy.cc
@@ -725,6 +725,10 @@ void SingleThreadProxy::ScheduledActionInvalidateCompositorFrameSink() {
   NOTREACHED();
 }
 
+void SingleThreadProxy::ScheduledActionPerformImplSideInvalidation() {
+  NOTIMPLEMENTED();
+}
+
 void SingleThreadProxy::UpdateBrowserControlsState(
     BrowserControlsState constraints,
     BrowserControlsState current,