Remove unnecessary image downloading handler of notifications.

chrome/browser/notifications/message_center_notifications_browsertest.cc

 // Copyright (c) 2013 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 <map>
 #include <string>
 
 #include "base/command_line.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 66 matching lines @@
     virtual void Close(bool by_user) override {
       log_ += "Close_";
       log_ += ( by_user ? "by_user_" : "programmatically_");
     }
     virtual void Click() override { log_ += "Click_"; }
     virtual void ButtonClick(int button_index) override {
       log_ += "ButtonClick_";
       log_ += base::IntToString(button_index) + "_";
     }
     virtual std::string id() const override { return id_; }
-    virtual content::WebContents* GetWebContents() const override {
-      return NULL;
-    }
 
     const std::string& log() { return log_; }
 
    private:
     virtual ~TestDelegate() {}
     std::string id_;
     std::string log_;
 
     DISALLOW_COPY_AND_ASSIGN(TestDelegate);
   };
@@ skipping 254 matching lines @@
   manager()->Update(notification, profile());
 
   // Expect that the progress notification update is performed.
   EXPECT_EQ(base::StringPrintf("update-%s", notification_id.c_str()),
             observer.log(notification_id));
 
   delegate->Release();
 }
 
 #endif  // !defined(OS_MACOSX)