Create a WebFrameWidget for WebViewPlugin.

components/plugins/renderer/webview_plugin.h

Index: components/plugins/renderer/webview_plugin.h
diff --git a/components/plugins/renderer/webview_plugin.h b/components/plugins/renderer/webview_plugin.h
index 74b4b1b226a1044bb813bd683ae6f6657f7ccbaf..20fa03886698f69d43e4e307c1cb8082ff3ce5bb 100644
--- a/components/plugins/renderer/webview_plugin.h
+++ b/components/plugins/renderer/webview_plugin.h
@@ -19,6 +19,7 @@
 #include "third_party/WebKit/public/web/WebViewClient.h"
 
 namespace blink {
+class WebFrameWidget;
 class WebMouseEvent;
 }
 
@@ -166,6 +167,9 @@ class WebViewPlugin : public blink::WebPlugin,
   blink::WebView* web_view_;
 
   // Owned by us, deleted via |close()|.
+  blink::WebFrameWidget* web_frame_widget_;
+
+  // Owned by us, deleted via |close()|.
   blink::WebFrame* web_frame_;
   gfx::Rect rect_;