Make RenderViewImpl::OnForceRedraw more robust

cc/trees/layer_tree_host_impl.h

Index: cc/trees/layer_tree_host_impl.h
diff --git a/cc/trees/layer_tree_host_impl.h b/cc/trees/layer_tree_host_impl.h
index 0870291de8104482be4cb8a6307652b1bc1c7434..fc523c8a7b04b89614c07b3e85008e79c5e1771c 100644
--- a/cc/trees/layer_tree_host_impl.h
+++ b/cc/trees/layer_tree_host_impl.h
@@ -462,6 +462,7 @@ class CC_EXPORT LayerTreeHostImpl
   }
   void QueueSwapPromiseForMainThreadScrollUpdate(
       std::unique_ptr<SwapPromise> swap_promise);
+  void QueueForcedRedrawSwapPromise(std::unique_ptr<SwapPromise> swap_promise);
 
   bool IsActivelyScrolling() const;
 
@@ -767,6 +768,7 @@ class CC_EXPORT LayerTreeHostImpl
   int scroll_layer_id_when_mouse_over_scrollbar_;
   std::vector<std::unique_ptr<SwapPromise>>
       swap_promises_for_main_thread_scroll_update_;
+  std::vector<std::unique_ptr<SwapPromise>> forced_redraw_swap_promises_;
 
   // An object to implement the ScrollElasticityHelper interface and
   // hold all state related to elasticity. May be NULL if never requested.