Prevented connecting drag drop events to a SwappedOut RenderViewHost in WebContentsViewGtk

content/port/browser/web_contents_view_port.h

 // Copyright (c) 2013 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 CONTENT_PORT_BROWSER_WEB_CONTENTS_VIEW_PORT_H_
 #define CONTENT_PORT_BROWSER_WEB_CONTENTS_VIEW_PORT_H_
 
 #include "content/public/browser/web_contents_view.h"
 
 namespace content {
@@ skipping 24 matching lines @@
   // is not strictly necessary and isn't expected to be displayed anywhere, but
   // can aid certain debugging tools such as Spy++ on Windows where you are
   // trying to find a specific window.
   virtual void SetPageTitle(const string16& title) = 0;
 
   // Invoked when the WebContents is notified that the RenderView has been
   // fully created.
   virtual void RenderViewCreated(RenderViewHost* host) = 0;
 
   // Invoked when the WebContents is notified that the RenderView has been
-  // swapped in.
-  virtual void RenderViewSwappedIn(RenderViewHost* host) = 0;
+  // swapped in. |old_host| may be null.

[Charlie Reis, 2013/02/27 01:42:35]

When will it be null, and what does that mean?

[mthiesse, 2013/02/27 14:57:13]

Well right now, never. I just didn't want to force the RenderViewSwappedIn call
to include an old host, as I'm not sure that is necessarily going to be true
going forward.

[Charlie Reis, 2013/02/27 20:01:44]

Let's avoid that case if we decide to keep old_host in the API.  It's much
better to provide clean values than make all callers check, so this should never
be null.

+  virtual void RenderViewSwappedIn(RenderViewHost* new_host,
+                                   RenderViewHost* old_host) = 0;
 
 #if defined(OS_MACOSX)
   // If we close the tab while a UI control is in an event-tracking
   // loop, the control may message freed objects and crash.
   // WebContents::Close() calls IsEventTracking(), and if it returns
   // true CloseTabAfterEventTracking() is called and the close is not
   // completed.
   virtual bool IsEventTracking() const = 0;
   virtual void CloseTabAfterEventTracking() = 0;
 #endif
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PORT_BROWSER_WEB_CONTENTS_VIEW_PORT_H_