Keeping track of descendants that draw content instead of recalcualting

cc/layers/delegated_renderer_layer_impl_unittest.cc

Index: cc/layers/delegated_renderer_layer_impl_unittest.cc
diff --git a/cc/layers/delegated_renderer_layer_impl_unittest.cc b/cc/layers/delegated_renderer_layer_impl_unittest.cc
index 33082cc6d2b70345e96c1f70922ea01caa6cd28a..8847c5c8bfe1285e042d9cecd9621c0e3ca63b4f 100644
--- a/cc/layers/delegated_renderer_layer_impl_unittest.cc
+++ b/cc/layers/delegated_renderer_layer_impl_unittest.cc
@@ -311,6 +311,8 @@ TEST_F(DelegatedRendererLayerImplTestSimple, DoesOwnARenderSurfaceForOpacity) {
   delegated_renderer_layer_->SetOpacity(0.5f);
 
   LayerTreeHostImpl::FrameData frame;
+  FakeLayerTreeHostImpl::RecursiveUpdateNumChildren(
+      host_impl_->active_tree()->root_layer());
   EXPECT_EQ(DRAW_SUCCESS, host_impl_->PrepareToDraw(&frame));
 
   // This test case has quads from multiple layers in the delegated renderer, so
@@ -329,6 +331,8 @@ TEST_F(DelegatedRendererLayerImplTestSimple,
   delegated_renderer_layer_->SetTransform(rotation);
 
   LayerTreeHostImpl::FrameData frame;
+  FakeLayerTreeHostImpl::RecursiveUpdateNumChildren(
+      host_impl_->active_tree()->root_layer());
   EXPECT_EQ(DRAW_SUCCESS, host_impl_->PrepareToDraw(&frame));
 
   // This test case has quads from multiple layers in the delegated renderer, so