Always use the WebFrameWidget when attaching the root graphics

third_party/WebKit/Source/web/tests/FrameTestHelpers.cpp

Index: third_party/WebKit/Source/web/tests/FrameTestHelpers.cpp
diff --git a/third_party/WebKit/Source/web/tests/FrameTestHelpers.cpp b/third_party/WebKit/Source/web/tests/FrameTestHelpers.cpp
index 438ebbfced6fda0aebe8d7233695c8fcb7aa4061..bb2a75404b9abfc7c546135053db949ec132e942 100644
--- a/third_party/WebKit/Source/web/tests/FrameTestHelpers.cpp
+++ b/third_party/WebKit/Source/web/tests/FrameTestHelpers.cpp
@@ -309,5 +309,20 @@ void TestWebViewClient::initializeLayerTreeView()
     m_layerTreeView = adoptPtr(new WebLayerTreeViewImplForTesting);
 }
 
+void TestWebViewWidgetClient::initializeLayerTreeView()
+{
+    m_testWebViewClient->initializeLayerTreeView();

[dcheng, 2016/06/08 00:10:17]

I don't think I understand why we need this forwarding client: we haven't
removed anything from the public interface.

[lfg, 2016/06/08 21:09:47]

I switched TestWebWidgetClient to be a class instead of an empty implementation
(this was needed because I had to override allowsBrokenNullLayerTreeView() in
tests that needed a frame widget). After that, TestWebViewClient can't be casted
to TestWebWidgetClient anymore, so I added the forwarding code -- it's basically
the same issue we have with WebFrameWidgetImpl/WebViewFrameWidget/WebViewImpl.

+}
+
+WebLayerTreeView* TestWebViewWidgetClient::layerTreeView()
+{
+    return m_testWebViewClient->layerTreeView();
+}
+
+void TestWebViewWidgetClient::scheduleAnimation()
+{
+    m_testWebViewClient->scheduleAnimation();
+}
+
 } // namespace FrameTestHelpers
 } // namespace blink