Change FrameTree to return Frames instead of LocalFrames.

Source/core/page/CreateWindow.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 50 matching lines @@
     if (openerFrame.document()->isSandboxed(SandboxPopups)) {
         // FIXME: This message should be moved off the console once a solution to https://bugs.webkit.org/show_bug.cgi?id=103274 exists.
         openerFrame.document()->addConsoleMessage(SecurityMessageSource, ErrorMessageLevel, "Blocked opening '" + request.resourceRequest().url().elidedString() + "' in a new window because the request was made in a sandboxed frame whose 'allow-popups' permission is not set.");
         return 0;
     }
 
     if (openerFrame.settings() && !openerFrame.settings()->supportsMultipleWindows()) {
         created = false;
         if (!openerFrame.tree().top()->isLocalFrame())
             return 0;
-        return openerFrame.tree().top();
+        return toLocalFrame(openerFrame.tree().top());
     }
 
     Page* oldPage = openerFrame.page();
     if (!oldPage)
         return 0;
 
     Page* page = oldPage->chrome().client().createWindow(&openerFrame, request, features, policy, shouldSendReferrer);
     if (!page)
         return 0;
     FrameHost* host = &page->frameHost();
@@ skipping 101 matching lines @@
     if (shouldSendReferrer == MaybeSendReferrer) {
         newFrame->loader().setOpener(&openerFrame);
         newFrame->document()->setReferrerPolicy(openerFrame.document()->referrerPolicy());
     }
     FrameLoadRequest newRequest(0, request.resourceRequest());
     newRequest.setFormState(request.formState());
     newFrame->loader().load(newRequest);
 }
 
 } // namespace WebCore