Update from https://crrev.com/308996

cc/test/scheduler_test_common.h

Index: cc/test/scheduler_test_common.h
diff --git a/cc/test/scheduler_test_common.h b/cc/test/scheduler_test_common.h
index ea6b2ef50d24b23fae5ed80994f4b39fb3f64a3d..d1e599d20f74c8337bed04f0ae7edd4f0055ae88 100644
--- a/cc/test/scheduler_test_common.h
+++ b/cc/test/scheduler_test_common.h
@@ -182,10 +182,19 @@ class TestScheduler : public Scheduler {
     return begin_retro_frame_args_.empty();
   }
 
+  bool CanStart() const { return state_machine_.CanStartForTesting(); }
+
   BeginFrameSource& frame_source() { return *frame_source_; }
 
   ~TestScheduler() override;
 
+  void NotifyReadyToCommitThenActivateIfNeeded() {
+    NotifyReadyToCommit();
+    if (settings_.impl_side_painting) {
+      NotifyReadyToActivate();
+    }
+  }
+
  protected:
   // Overridden from Scheduler.
   base::TimeTicks Now() const override;