Add enum that specifies the frame detachment reason.

public/web/WebFrameClient.h

Index: public/web/WebFrameClient.h
diff --git a/public/web/WebFrameClient.h b/public/web/WebFrameClient.h
index 1de7df29d595279f9b1c92d9de8619fe6e361a81..732c7a885a085cab3fbd36e4e30c803b1de2f2ff 100644
--- a/public/web/WebFrameClient.h
+++ b/public/web/WebFrameClient.h
@@ -155,6 +155,9 @@ public:
     // 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*) { }