Update BaseBubbleController's dealloc function to use

chrome/browser/ui/cocoa/base_bubble_controller.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/base_bubble_controller.h"
 
 #include "base/logging.h"
 #include "base/mac/bundle_locations.h"
 #include "base/mac/foundation_util.h"
 #include "base/mac/mac_util.h"
@@ skipping 98 matching lines @@
     TabStripController* tabStripController = [bwc tabStripController];
     TabStripModel* tabStripModel = [tabStripController tabStripModel];
     tabStripObserverBridge_.reset(new TabStripModelObserverBridge(tabStripModel,
                                                                   self));
   }
 
   [bubble_ setArrowLocation:info_bubble::kTopRight];
 }
 
 - (void)dealloc {
-  [[NSNotificationCenter defaultCenter] removeObserver:self];
+  [self unregisterFromNotifications];
   [super dealloc];
 }
 
 - (void)registerForNotifications {
   // No window to register notifications for.
   if (!parentWindow_)
     return;
 
   NSNotificationCenter* center = [NSNotificationCenter defaultCenter];
   // Watch to see if the parent window closes, and if so, close this one.
@@ skipping 317 matching lines @@
 
 - (void)activateTabWithContents:(content::WebContents*)newContents
                previousContents:(content::WebContents*)oldContents
                         atIndex:(NSInteger)index
                          reason:(int)reason {
   // The user switched tabs; close.
   [self closeBubble];
 }
 
 @end  // BaseBubbleController