Adds BeginFrameControl via DevTools.

cc/surfaces/display_scheduler_unittest.cc

Index: cc/surfaces/display_scheduler_unittest.cc
diff --git a/cc/surfaces/display_scheduler_unittest.cc b/cc/surfaces/display_scheduler_unittest.cc
index ea7a22fba5a84d9bf54d197f19a0911a4101c81e..69a0b275bd6f6bb0e642b847d3354c69b95c7599 100644
--- a/cc/surfaces/display_scheduler_unittest.cc
+++ b/cc/surfaces/display_scheduler_unittest.cc
@@ -32,6 +32,8 @@ class FakeDisplaySchedulerClient : public DisplaySchedulerClient {
     return true;
   }
 
+  SurfaceManager* GetSurfaceManager() const override { return nullptr; }
+
   void Reset() { draw_and_swap_count_ = 0; }
 
   int draw_and_swap_count() const { return draw_and_swap_count_; }