Add UMA histogram data representing the Synced Notifications feature.

chrome/browser/notifications/sync_notifier/chrome_notifier_delegate.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 "chrome/browser/notifications/sync_notifier/chrome_notifier_delegate.h"
 
 #include "chrome/browser/notifications/sync_notifier/chrome_notifier_service.h"
 #include "chrome/browser/notifications/sync_notifier/synced_notification.h"
+#include "chrome/browser/notifications/sync_notifier/synced_notification_stats.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "content/public/browser/page_navigator.h"
 
 namespace notifier {
 ChromeNotifierDelegate::ChromeNotifierDelegate(
     const std::string& notification_id,
     ChromeNotifierService* notifier)
     : notification_id_(notification_id), chrome_notifier_(notifier) {}
 
@@ skipping 10 matching lines @@
 // TODO(petewil) Add the ability to do URL actions also.
 void ChromeNotifierDelegate::Click() {
   SyncedNotification* notification =
       chrome_notifier_->FindNotificationById(notification_id_);
   if (notification == NULL)
     return;
 
   GURL destination = notification->GetDefaultDestinationUrl();
   NavigateToUrl(destination);
   chrome_notifier_->MarkNotificationAsRead(notification_id_);
+
+  // Record the action in UMA statistics.
+  SyncedNotificationStats notification_stat;
+  StatsCollection::iterator iter = stats_.find(notification_id_);
+  if (iter == stats_.end()) {
+    notification_stat = SyncedNotificationStats(notification_id_);
+    stats_[notification_id_] = notification_stat;
+  } else {
+    notification_stat = iter->second;
+  }
+
+  notification_stat.CollectAction(SYNCED_NOTIFICATION_ACTION_CLICK);
 }
 
 // TODO(petewil) Add the ability to do URL actions also.
 void ChromeNotifierDelegate::ButtonClick(int button_index) {
   SyncedNotification* notification =
       chrome_notifier_->FindNotificationById(notification_id_);
   if (notification) {
     GURL destination = notification->GetButtonUrl(button_index);
     NavigateToUrl(destination);
     chrome_notifier_->MarkNotificationAsRead(notification_id_);
   }
+
+  // Now record the UMA statistics for this action.
+  SyncedNotificationStats notification_stat;
+  StatsCollection::iterator iter = stats_.find(notification_id_);
+  if (iter == stats_.end()) {
+    notification_stat = SyncedNotificationStats(notification_id_);
+    stats_[notification_id_] = notification_stat;
+  } else {
+    notification_stat = iter->second;
+  }
+
+  notification_stat.CollectAction(SYNCED_NOTIFICATION_ACTION_BUTTON_CLICK);

[Alexei Svitkine (slow), 2013/10/17 16:38:00]

I don't think you need the new class and a map of collectors anymore.

Simply make CollectAction() a free-standing function at the top of the file in
an anon namespace along with the enum declaration.

Them, just call it on its own from all the places you need to, without the logic
to find/insert the StatsCollection object and remove that class completely.

 }
 
 void ChromeNotifierDelegate::NavigateToUrl(const GURL& destination) const {
   if (!destination.is_valid())
     return;
 
   content::OpenURLParams openParams(destination, content::Referrer(),
                                     NEW_FOREGROUND_TAB,
                                     content::PAGE_TRANSITION_LINK, false);
   Browser* browser = chrome::FindLastActiveWithProfile(
       chrome_notifier_->profile(),
       chrome::GetActiveDesktop());
   // Navigate to the URL in a new tab.
   if (browser != NULL)
     browser->OpenURL(openParams);
 
 }
 
 void ChromeNotifierDelegate::Close(bool by_user) {
   if (by_user)
     chrome_notifier_->MarkNotificationAsRead(notification_id_);
+
+  StatsCollection::iterator iter = stats_.find(notification_id_);
+  if (iter == stats_.end())
+    return;
+  SyncedNotificationStats& notification_stat = iter->second;
+  notification_stat.CollectAction(by_user ?
+      SYNCED_NOTIFICATION_ACTION_CLOSE_BY_USER :
+      SYNCED_NOTIFICATION_ACTION_CLOSE_BY_SYSTEM);
+  stats_.erase(notification_id_);
 }
 
 }  // namespace notifier