Fixing flakiness of TextureLayerChangeInvisibleMailboxTest

cc/test/layer_tree_test.cc

Index: cc/test/layer_tree_test.cc
diff --git a/cc/test/layer_tree_test.cc b/cc/test/layer_tree_test.cc
index 60077ec082d0e944523091ef1d2a3514f9fb6a84..94dd0a7ff549429c101f80d77d10b3ecf6ce4d67 100644
--- a/cc/test/layer_tree_test.cc
+++ b/cc/test/layer_tree_test.cc
@@ -279,6 +279,12 @@ class LayerTreeHostImplForTesting : public LayerTreeHostImpl {
     test_hooks_->DidRequestImplSideInvalidation(this);
   }
 
+  void DidReceiveCompositorFrameAck() override {
+    test_hooks_->WillReceiveCompositorFrameAckOnImplThread();
+    LayerTreeHostImpl::DidReceiveCompositorFrameAck();
+    test_hooks_->DidReceiveCompositorFrameAckOnImplThread();
+  }
+
   AnimationHost* animation_host() const {
     return static_cast<AnimationHost*>(mutator_host());
   }