Disallow local/remote checks on subclasses of Frame, FrameOwner and DOMWindow.

third_party/WebKit/Source/core/frame/RemoteFrame.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef RemoteFrame_h
 #define RemoteFrame_h
 
 #include "core/CoreExport.h"
 #include "core/dom/RemoteSecurityContext.h"
 #include "core/frame/Frame.h"
@@ skipping 12 matching lines @@
 struct FrameLoadRequest;
 
 class CORE_EXPORT RemoteFrame: public Frame {
 public:
     static RemoteFrame* create(RemoteFrameClient*, FrameHost*, FrameOwner*);
 
     ~RemoteFrame() override;
 
     // Frame overrides:
     DECLARE_VIRTUAL_TRACE();
-    bool isRemoteFrame() const override { return true; }
     DOMWindow* domWindow() const override;
     WindowProxy* windowProxy(DOMWrapperWorld&) override;
     void navigate(Document& originDocument, const KURL&, bool replaceCurrentItem, UserGestureStatus) override;
     void navigate(const FrameLoadRequest& passedRequest) override;
     void reload(FrameLoadType, ClientRedirectPolicy) override;
     void detach(FrameDetachType) override;
     RemoteSecurityContext* securityContext() const override;
     void printNavigationErrorMessage(const Frame&, const char* reason) override { }
     bool prepareForCommit() override;
     bool shouldClose() override;
@@ skipping 16 matching lines @@
 
     RemoteFrameView* view() const;
 
     RemoteFrameClient* client() const;
 
 private:
     RemoteFrame(RemoteFrameClient*, FrameHost*, FrameOwner*);
 
     // Internal Frame helper overrides:
     WindowProxyManager* getWindowProxyManager() const override { return m_windowProxyManager.get(); }
+    // Intentionally private to prevent redundant checks when the type is
+    // already RemoteFrame.
+    using Frame::isLocalFrame;
+    bool isRemoteFrame() const override { return true; }
 
     Member<RemoteFrameView> m_view;
     Member<RemoteSecurityContext> m_securityContext;
     Member<RemoteDOMWindow> m_domWindow;
     Member<WindowProxyManager> m_windowProxyManager;
     WebLayer* m_remotePlatformLayer;
 };
 
 inline RemoteFrameView* RemoteFrame::view() const
 {
     return m_view.get();
 }
 
 DEFINE_TYPE_CASTS(RemoteFrame, Frame, remoteFrame, remoteFrame->isRemoteFrame(), remoteFrame.isRemoteFrame());
 
 } // namespace blink
 
 #endif // RemoteFrame_h