Revert of Detach old frame on WebFrame::swap.

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 15 matching lines @@
     virtual ~RemoteFrame();
 
     // 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 lockBackForwardList, UserGestureStatus) override;
     void navigate(const FrameLoadRequest& passedRequest) override;
     void reload(FrameLoadType, ClientRedirectPolicy) override;
-    void detach(FrameDetachType) override;
+    void detach() override;
     RemoteSecurityContext* securityContext() const override;
     void printNavigationErrorMessage(const Frame&, const char* reason) override { }
     void disconnectOwnerElement() override;
-    bool prepareForCommit() override;
 
     // FIXME: Remove this method once we have input routing in the browser
     // process. See http://crbug.com/339659.
     void forwardInputEvent(Event*);
 
     void setRemotePlatformLayer(WebLayer*);
     WebLayer* remotePlatformLayer() const { return m_remotePlatformLayer; }
 
     void setView(PassRefPtrWillBeRawPtr<RemoteFrameView>);
     void createView();
@@ skipping 18 matching lines @@
 inline RemoteFrameView* RemoteFrame::view() const
 {
     return m_view.get();
 }
 
 DEFINE_TYPE_CASTS(RemoteFrame, Frame, remoteFrame, remoteFrame->isRemoteFrame(), remoteFrame.isRemoteFrame());
 
 } // namespace blink
 
 #endif // RemoteFrame_h