[Mac] Address buggy permission bubble behaviour on dismissal via ESC.

chrome/browser/permissions/permission_request_manager.h

Index: chrome/browser/permissions/permission_request_manager.h
diff --git a/chrome/browser/permissions/permission_request_manager.h b/chrome/browser/permissions/permission_request_manager.h
index def150e1a9606b7fe9b8f6fa147475115d17db07..e94c2c122adbb24b4a307541a881213f23de8a06 100644
--- a/chrome/browser/permissions/permission_request_manager.h
+++ b/chrome/browser/permissions/permission_request_manager.h
@@ -70,7 +70,14 @@ class PermissionRequestManager
   // at which time the caller is free to delete the request.
   void CancelRequest(PermissionRequest* request);
 
-  // Hides the bubble.
+  // Dismisses the bubble if it is visible, as if the user had clicked the X in
+  // the prompt. Then hides the bubble and destroys the UI surface used to
+  // display permission requests.

[raymes, 2016/10/26 04:59:11]

Could you add a note here that this is only used on Mac and shouldn't be called
anywhere else. And also a TODO to remove this once we switch to views?

[dominickn, 2016/10/26 05:54:23]

I don't want to do that yet, because at some point I need to investigate if this
is an issue on views too (the bugs linked claims that it's not, but I'm
suspicious and want to verify).

[raymes, 2016/10/27 01:42:57]

Can we add a TODO to that effect then, with a bug link? Something saying that
it's currently only needed for Mac and may not be needed at all, but should be
investigated? It would be good to steer people away from using this if we will
get rid of it.

+  void DismissBubble();
+
+  // Temporarily hides the bubble, and destroys the prompt UI surface. Any
+  // existing requests will be reshown when DisplayPendingRequests is called
+  // (e.g. when switching tabs away and back to a page with a prompt).
   void HideBubble();
 
   // Will show a permission bubble if there is a pending permission request on