Add enum that specifies the frame detachment reason.

public/web/WebFrameClient.h

 /*
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 137 matching lines @@
     // frame and returns a new WebFrame. The WebFrame is considered in-use
     // until frameDetached() is called on it.
     // Note: If you override this, you should almost certainly be overriding
     // frameDetached().
     virtual WebFrame* createChildFrame(WebLocalFrame* parent, WebTreeScopeType, const WebString& frameName, WebSandboxFlags sandboxFlags) { return nullptr; }
 
     // This frame set its opener to null, disowning it.
     // See http://html.spec.whatwg.org/#dom-opener.
     virtual void didDisownOpener(WebLocalFrame*) { }
 
+    // Specifies the reason for the detachment.
+    enum WebDetachReason { Remove, Swap };

[dcheng, 2015/06/01 20:06:46]

enum class instead of enum.

Also, let's call this "DetachType" (nasko@ came up with this at lunch), with no
Web prefix.

[lfg, 2015/06/01 20:22:15]

Done.

+
     // This frame has been detached from the view, but has not been closed yet.
     virtual void frameDetached(WebFrame*) { }
 
     // This frame has become focused..
     virtual void frameFocused() { }
 
     // This frame is about to be closed. This is called after frameDetached,
     // when the document is being unloaded, due to new one committing.
     virtual void willClose(WebFrame*) { }
 
@@ skipping 475 matching lines @@
     // App Banners ---------------------------------------------------------
     virtual WebAppBannerClient* appBannerClient() { return 0; }
 
 protected:
     virtual ~WebFrameClient() { }
 };
 
 } // namespace blink
 
 #endif