Prevent recreation of UI resource holder when created with resource ID

cc/layers/ui_resource_layer_unittest.cc

Index: cc/layers/ui_resource_layer_unittest.cc
diff --git a/cc/layers/ui_resource_layer_unittest.cc b/cc/layers/ui_resource_layer_unittest.cc
index 09d57a96520de55b498ce908fe2aa487af38e858..3855c6c6d5fcb282c4568026d705d6c9b607765d 100644
--- a/cc/layers/ui_resource_layer_unittest.cc
+++ b/cc/layers/ui_resource_layer_unittest.cc
@@ -102,6 +102,14 @@ TEST_F(UIResourceLayerTest, SetUIResourceId) {
   test_layer->Update(&queue, &occlusion_tracker);
 
   EXPECT_TRUE(test_layer->DrawsContent());
+
+  // ID is preserved even when you set ID first and attach it to the tree.
+  scoped_refptr<UIResourceLayer> new_test_layer = UIResourceLayer::Create();
+  scoped_ptr<ScopedUIResource> new_resource = ScopedUIResource::Create(
+      layer_tree_host_.get(), UIResourceBitmap(gfx::Size(5, 5), is_opaque));
+  new_test_layer->SetUIResourceId(new_resource->id());
+  test_layer->AddChild(new_test_layer);
+  EXPECT_EQ(new_resource->id(), new_test_layer->GetUIResourceId());
 }
 
 }  // namespace