cc: Emulate BeginFrame in OutputSurfaces that don't support it natively

cc/scheduler/scheduler_unittest.cc

Index: cc/scheduler/scheduler_unittest.cc
diff --git a/cc/scheduler/scheduler_unittest.cc b/cc/scheduler/scheduler_unittest.cc
index 68aecaf9dc5794947668df2103ea45e08b093b80..5f85966810fb022c99d27c2af1cc181feb8e2282 100644
--- a/cc/scheduler/scheduler_unittest.cc
+++ b/cc/scheduler/scheduler_unittest.cc
@@ -68,6 +68,10 @@ class FakeSchedulerClient : public SchedulerClient {
   }
 
   // Scheduler Implementation.
+  virtual void SetNeedsBeginFrameOnImplThread(bool enable) OVERRIDE {
+    actions_.push_back("SetNeedsBeginFrameOnImplThread");
+    states_.push_back(scheduler_->StateAsStringForTesting());
+  }
   virtual void ScheduledActionSendBeginFrameToMainThread() OVERRIDE {
     actions_.push_back("ScheduledActionSendBeginFrameToMainThread");
     states_.push_back(scheduler_->StateAsStringForTesting());