Make sure keybindings removed don't come back during extension update.

chrome/browser/ui/views/browser_action_view.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/ui/views/browser_action_view.h"
 
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/extensions/api/commands/command_service.h"
 #include "chrome/browser/extensions/extension_action.h"
 #include "chrome/browser/extensions/extension_action_manager.h"
@@ skipping 389 matching lines @@
   extensions::CommandService* command_service =
       extensions::CommandService::Get(browser_->profile());
 
   extensions::Command browser_action_command;
   if (!only_if_active || !command_service->GetBrowserActionCommand(
           extension_->id(),
           extensions::CommandService::ACTIVE_ONLY,
           &browser_action_command,
           NULL)) {
     GetFocusManager()->UnregisterAccelerator(*keybinding_.get(), this);
+    keybinding_.reset(NULL);

[Yoyo Zhou, 2013/05/06 18:47:58]

Why is this views-only?

[Finnur, 2013/05/06 23:13:54]

Good question. This was something I discovered by the test I wrote for this CL.
If we don't reset this, then destroying the button will trigger us to try to
unregister this keybinding again and the FocusManager will DCHECK because the
keybinding isn't registered (naturally). That doesn't happen on other platforms
(as keybindings are handled differently on each platform).

   }
 }