Revert of Detach old frame on WebFrame::swap.

public/web/WebRemoteFrameClient.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 WebRemoteFrameClient_h
 #define WebRemoteFrameClient_h
 
 #include "public/platform/WebSecurityOrigin.h"
 #include "public/web/WebDOMMessageEvent.h"
 
 namespace blink {
 class WebInputEvent;
 class WebLocalFrame;
 class WebRemoteFrame;
 struct WebRect;
 
 class WebRemoteFrameClient {
 public:
     // Specifies the reason for the detachment.
     enum class DetachType { Remove, Swap };
 
     // Notify the embedder that it should remove this frame from the frame tree
     // and release any resources associated with it.
-    virtual void frameDetached(DetachType) { }
+    virtual void frameDetached() { }
 
     // Notifies the embedder that a postMessage was issued to a remote frame.
     virtual void postMessageEvent(
         WebLocalFrame* sourceFrame,
         WebRemoteFrame* targetFrame,
         WebSecurityOrigin targetOrigin,
         WebDOMMessageEvent) { }
 
     // Send initial drawing parameters to a child frame that is being rendered
     // out of process.
     virtual void initializeChildFrame(
         const WebRect& frameRect,
         float scaleFactor) { }
 
     // A remote frame was asked to start a navigation.
     virtual void navigate(const WebURLRequest& request, bool shouldReplaceCurrentEntry) { }
     virtual void reload(bool ignoreCache, bool isClientRedirect) { }
 
     // FIXME: Remove this method once we have input routing in the browser
     // process. See http://crbug.com/339659.
     virtual void forwardInputEvent(const WebInputEvent*) { }
 };
 
 } // namespace blink
 
 #endif // WebRemoteFrameClient_h