[Cocoa] Crash fix, caused by recent tab indicator change.

chrome/browser/ui/cocoa/tabs/tab_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/tabs/tab_controller.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/i18n/rtl.h"
@@ skipping 110 matching lines @@
                       selector:@selector(themeChangedNotification:)
                           name:kBrowserThemeDidChangeNotification
                         object:nil];
 
     [self internalSetSelected:selected_];
   }
   return self;
 }
 
 - (void)dealloc {
+  [mediaIndicatorButton_ setAnimationDoneTarget:nil withAction:nil];
+  [mediaIndicatorButton_ setClickTarget:nil withAction:nil];
   [[NSNotificationCenter defaultCenter] removeObserver:self];
   [[self tabView] setController:nil];
   [super dealloc];
 }
 
 // The internals of |-setSelected:| and |-setActive:| but doesn't set the
 // backing variables. This updates the drawing state and marks self as needing
 // a re-draw.
 - (void)internalSetSelected:(BOOL)selected {
   TabView* tabView = [self tabView];
@@ skipping 304 matching lines @@
 // TabStripDragController.
 - (BOOL)tabCanBeDragged:(TabController*)controller {
   return [[target_ dragController] tabCanBeDragged:controller];
 }
 
 - (void)maybeStartDrag:(NSEvent*)event forTab:(TabController*)tab {
   [[target_ dragController] maybeStartDrag:event forTab:tab];
 }
 
 @end