Add WebWidgetTestProxy.

third_party/WebKit/public/web/WebWidget.h

Index: third_party/WebKit/public/web/WebWidget.h
diff --git a/third_party/WebKit/public/web/WebWidget.h b/third_party/WebKit/public/web/WebWidget.h
index bc0a6faeadee75a26c1916d92d571baf15aba835..fa3c4fab267f362e56a6e28ebf5a7e6cbe5b5d96 100644
--- a/third_party/WebKit/public/web/WebWidget.h
+++ b/third_party/WebKit/public/web/WebWidget.h
@@ -208,6 +208,10 @@ public:
 
     // Returns true if the WebWidget created is of type WebView.
     virtual bool isWebView() const { return false; }
+
+    // Returns true if the WebWidget created is of type WebFrameWidget.
+    virtual bool isWebFrameWidget() const { return false; }
+
     // Returns true if the WebWidget created is of type WebPagePopup.
     virtual bool isPagePopup() const { return false; }