[Mac] Stop listening for NSWindowWillCloseNotification in |-dealloc| to fix a crash.

chrome/browser/ui/cocoa/hung_renderer_controller_unittest.mm

 // Copyright (c) 2011 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 <Cocoa/Cocoa.h>
 
 #import "base/memory/scoped_nsobject.h"
 #include "chrome/browser/ui/cocoa/cocoa_test_helper.h"
 #import "chrome/browser/ui/cocoa/hung_renderer_controller.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/platform_test.h"
 
 namespace {
 
 class HungRendererControllerTest : public CocoaTest {
  public:
   virtual void SetUp() {
     CocoaTest::SetUp();
     hung_renderer_controller_ = [[HungRendererController alloc]
                                   initWithWindowNibName:@"HungRendererDialog"];
   }
   HungRendererController* hung_renderer_controller_;  // owned by its window
 };
 
-TEST_F(HungRendererControllerTest, FLAKY_TestShowAndClose) {
+TEST_F(HungRendererControllerTest, TestShowAndClose) {
   // Doesn't test much functionality-wise, but makes sure we can
   // display and tear down a window.
   [hung_renderer_controller_ showWindow:nil];
   // Cannot call performClose:, because the close button is disabled.
   [hung_renderer_controller_ close];
 }
 
 TEST_F(HungRendererControllerTest, TestKillButton) {
   // We can't test killing a process because we have no running
   // process to kill, but we can make sure that pressing the kill
   // button closes the window.
   [hung_renderer_controller_ showWindow:nil];
   [[hung_renderer_controller_ killButton] performClick:nil];
 }
 
 TEST_F(HungRendererControllerTest, TestWaitButton) {
   // We can't test waiting because we have no running process to wait
   // for, but we can make sure that pressing the wait button closes
   // the window.
   [hung_renderer_controller_ showWindow:nil];
   [[hung_renderer_controller_ waitButton] performClick:nil];
 }
 
 }  // namespace