Remove unnecessary image downloading handler of notifications.

chrome/browser/background/background_contents_service.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/background/background_contents_service.h"
 
 #include "apps/app_load_service.h"
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 129 matching lines @@
     // be OK, but it causes a crash on Mac, see: http://crbug.com/78167
     ScheduleCloseBalloon(copied_extension_id, profile_);
   }
 
   virtual bool HasClickedListener() override { return true; }
 
   virtual std::string id() const override {
     return kNotificationPrefix + extension_id_;
   }
 
-  virtual content::WebContents* GetWebContents() const override {
-    return NULL;
-  }
-
  private:
   virtual ~CrashNotificationDelegate() {}
 
   Profile* profile_;
   bool is_hosted_app_;
   bool is_platform_app_;
   std::string extension_id_;
 
   DISALLOW_COPY_AND_ASSIGN(CrashNotificationDelegate);
 };
@@ skipping 616 matching lines @@
     bool user_gesture,
     bool* was_blocked) {
   Browser* browser = chrome::FindLastActiveWithProfile(
       Profile::FromBrowserContext(new_contents->GetBrowserContext()),
       chrome::GetActiveDesktop());
   if (browser) {
     chrome::AddWebContents(browser, NULL, new_contents, disposition,
                            initial_pos, user_gesture, was_blocked);
   }
 }