Add histograms for notification icons.

content/child/notifications/notification_image_loader.h

 // Copyright 2014 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.
 
 #ifndef CONTENT_CHILD_NOTIFICATIONS_NOTIFICATION_IMAGE_LOADER_H_
 #define CONTENT_CHILD_NOTIFICATIONS_NOTIFICATION_IMAGE_LOADER_H_
 
 #include <stdint.h>
 
 #include <vector>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/sequenced_task_runner_helpers.h"
+#include "base/time/time.h"
 #include "third_party/WebKit/public/platform/WebURLLoaderClient.h"
 
 class GURL;
 class SkBitmap;
 
 namespace base {
 class SingleThreadTaskRunner;
 }
 
 namespace blink {
@@ skipping 65 matching lines @@
 
   scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner_;
   scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
 
   bool completed_;
 
   scoped_ptr<blink::WebURLLoader> url_loader_;
 
   std::vector<uint8_t> buffer_;
 
+  base::TimeTicks start_time_;
+
   DISALLOW_COPY_AND_ASSIGN(NotificationImageLoader);
 };
 
 struct NotificationImageLoaderDeleter {
   static void Destruct(const NotificationImageLoader* context) {
     context->DeleteOnCorrectThread();
   }
 };
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_NOTIFICATIONS_NOTIFICATION_IMAGE_LOADER_H_