Remove GoogleNowNotification stats collector

chrome/browser/notifications/google_now_notification_stats_collector.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 CHROME_BROWSER_NOTIFICATIONS_GOOGLE_NOW_NOTIFICATION_STATS_COLLECTOR_H_
-#define CHROME_BROWSER_NOTIFICATIONS_GOOGLE_NOW_NOTIFICATION_STATS_COLLECTOR_H_
-
-#include <string>
-
-#include "base/macros.h"
-#include "ui/message_center/message_center.h"
-#include "ui/message_center/message_center_observer.h"
-#include "ui/message_center/message_center_types.h"
-
-// The Google Now Notification Stats Collector listens for message center
-// events and records stats about Google Now specific notifications.
-class GoogleNowNotificationStatsCollector
-    : public message_center::MessageCenterObserver {
- public:
-  explicit GoogleNowNotificationStatsCollector(
-      message_center::MessageCenter* message_center);
-  ~GoogleNowNotificationStatsCollector() override;
-
- private:
-  // MessageCenterObserver
-  void OnNotificationDisplayed(
-      const std::string& notification_id,
-      const message_center::DisplaySource source) override;
-  void OnCenterVisibilityChanged(
-      message_center::Visibility visibility) override;
-
-  // Counts the number of Google Now Notifications in the message center.
-  int CountVisibleGoogleNowNotifications();
-
-  // Returns true if the ID of a visible notification is for Google Now.
-  bool IsVisibleNotificationIdForGoogleNow(const std::string& notification_id);
-
-  // Weak, global.
-  message_center::MessageCenter* message_center_;
-
-  DISALLOW_COPY_AND_ASSIGN(GoogleNowNotificationStatsCollector);
-};
-
-#endif  // CHROME_BROWSER_NOTIFICATIONS_GOOGLE_NOW_NOTIFICATION_STATS_COLLECTOR_H_