Remove unnecessary image downloading handler of notifications.

chrome/browser/notifications/notification_test_util.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/notifications/notification_test_util.h"
 
 MockNotificationDelegate::MockNotificationDelegate(const std::string& id)
     : id_(id) {}
 
 MockNotificationDelegate::~MockNotificationDelegate() {}
 
 std::string MockNotificationDelegate::id() const { return id_; }
 
-content::WebContents* MockNotificationDelegate::GetWebContents() const {
-  return NULL;
-}
-
 // TODO(peter): |notification_| should be initialized with the correct origin.
 StubNotificationUIManager::StubNotificationUIManager(const GURL& welcome_origin)
     : notification_(GURL(),
                     base::string16(),
                     base::string16(),
                     gfx::Image(),
                     base::string16(),
                     base::string16(),
                     new MockNotificationDelegate("stub")),
       profile_(NULL),
@@ skipping 51 matching lines @@
 bool StubNotificationUIManager::CancelAllBySourceOrigin(
     const GURL& source_origin) {
   return false;
 }
 
 bool StubNotificationUIManager::CancelAllByProfile(ProfileID profile_id) {
   return false;
 }
 
 void StubNotificationUIManager::CancelAll() {}