Adds BeginFrameControl via DevTools.

ui/compositor/test/in_process_context_factory.h

Index: ui/compositor/test/in_process_context_factory.h
diff --git a/ui/compositor/test/in_process_context_factory.h b/ui/compositor/test/in_process_context_factory.h
index 54266ba4e226eccaeec1eb086877515143e346b5..3d01bbd51a6901f7f350bac99b584fdce4764a46 100644
--- a/ui/compositor/test/in_process_context_factory.h
+++ b/ui/compositor/test/in_process_context_factory.h
@@ -67,6 +67,9 @@ class InProcessContextFactory : public ContextFactory {
   void SetDisplayVSyncParameters(ui::Compositor* compositor,
                                  base::TimeTicks timebase,
                                  base::TimeDelta interval) override {}
+  void SwapBeginFrameSource(
+      ui::Compositor* compositor,
+      std::unique_ptr<cc::BeginFrameSource>* begin_frame_source) override {}
   void SetOutputIsSecure(ui::Compositor* compositor, bool secure) override {}
   void AddObserver(ContextFactoryObserver* observer) override;
   void RemoveObserver(ContextFactoryObserver* observer) override;