Bug 1044736 - Part 2. Add nsIBrowserElementAPI.idl and implement nsBrowserElement. r=bz

dom/html/nsGenericHTMLFrameElement.h

@@ -34,6 +34,7 @@ public:
                             mozilla::dom::FromParser aFromParser)
     : nsGenericHTMLElement(aNodeInfo)
     , nsElementFrameLoaderOwner(aFromParser)
+    , nsBrowserElement()
   {
   }
 
@@ -73,6 +74,19 @@ public:
 
   static bool BrowserFramesEnabled();
 
+  /**
+   * nsIFrameLoaderOwner defines two GetFrameLoader() overloads. One
+   * is XPCOM style interface, the other one is C++ only.  "using" pulls
+   * them both in, now GetFrameLoader() is ambiguous because
+   * nsBrowserElement also has GetFrameLoader(). Explicit redefine
+   * GetFrameLoader() to choose nsElementFrameLoaderOwner::GetFrameLoader()
+   */
+  using nsElementFrameLoaderOwner::GetFrameLoader;
+  virtual already_AddRefed<nsFrameLoader> GetFrameLoader() MOZ_OVERRIDE
+  {
+    return nsElementFrameLoaderOwner::GetFrameLoader();
+  }
+
   /**
    * Helper method to map a HTML 'scrolling' attribute value to a nsIScrollable
    * enum value.  scrolling="no" (and its synonyms) maps to