Always use the WebFrameWidget when attaching the root graphics

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

Index: third_party/WebKit/Source/web/tests/FrameTestHelpers.h
diff --git a/third_party/WebKit/Source/web/tests/FrameTestHelpers.h b/third_party/WebKit/Source/web/tests/FrameTestHelpers.h
index eaadcac7d7d09a7a698019190961e8c10243e710..27f14894dfebc6d2912ef453f4425e24d8c542dc 100644
--- a/third_party/WebKit/Source/web/tests/FrameTestHelpers.h
+++ b/third_party/WebKit/Source/web/tests/FrameTestHelpers.h
@@ -59,7 +59,8 @@ enum class WebCachePolicy;
 namespace FrameTestHelpers {
 
 class TestWebFrameClient;
-using TestWebWidgetClient = WebWidgetClient;
+class TestWebWidgetClient;
+class TestWebViewClient;
 
 // Loads a url into the specified WebFrame for testing purposes. Pumps any
 // pending resource requests, as well as waiting for the threaded parser to
@@ -117,9 +118,35 @@ private:
     bool m_originalOverlayScrollbarsEnabled;
 };
 
+class TestWebWidgetClient : public WebWidgetClient {
+public:
+    virtual ~TestWebWidgetClient() {}
+    bool allowsBrokenNullLayerTreeView() const override { return true; }
+};
+
+class TestWebViewWidgetClient : public TestWebWidgetClient {
+public:
+    TestWebViewWidgetClient(TestWebViewClient* testWebViewClient)

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

Nit: explicit

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

Done.

+        : m_testWebViewClient(testWebViewClient)
+    {
+    }
+    virtual ~TestWebViewWidgetClient() {}
+
+    void initializeLayerTreeView() override;
+    WebLayerTreeView* layerTreeView() override;
+    void scheduleAnimation() override;
+
+private:
+    TestWebViewClient* m_testWebViewClient;
+};
+
 class TestWebViewClient : public WebViewClient {
 public:
-    TestWebViewClient() : m_animationScheduled(false) { }
+    TestWebViewClient()
+        : m_testWebWidgetClient(this)
+        , m_animationScheduled(false)
+    {
+    }
     virtual ~TestWebViewClient() { }
     void initializeLayerTreeView() override;
     WebLayerTreeView* layerTreeView() override { return m_layerTreeView.get(); }
@@ -131,9 +158,10 @@ public:
     // TODO(lfg): This is a temporary method to retrieve the WebWidgetClient,
     // while we refactor WebView to not inherit from Webwidget.
     // Returns the WebWidgetClient.
-    WebWidgetClient* widgetClient() { return this; }
+    TestWebWidgetClient* widgetClient() { return &m_testWebWidgetClient; }
 
 private:
+    TestWebViewWidgetClient m_testWebWidgetClient;
     OwnPtr<WebLayerTreeView> m_layerTreeView;
     bool m_animationScheduled;
 };