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"
 
+

[Alexei Svitkine (slow), 2013/10/18 13:09:08]

Nit: Remove extra blank line?

+#include "base/metrics/histogram.h"
 #include "chrome/browser/notifications/sync_notifier/chrome_notifier_service.h"
 #include "chrome/browser/notifications/sync_notifier/synced_notification.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "content/public/browser/page_navigator.h"
+#include "content/public/browser/user_metrics.h"
 
 namespace notifier {
 ChromeNotifierDelegate::ChromeNotifierDelegate(
     const std::string& notification_id,
     ChromeNotifierService* notifier)
     : notification_id_(notification_id), chrome_notifier_(notifier) {}
 
 ChromeNotifierDelegate::~ChromeNotifierDelegate() {}
 
 std::string ChromeNotifierDelegate::id() const {
    return notification_id_;
 }
 
 content::RenderViewHost* ChromeNotifierDelegate::GetRenderViewHost() const {
     return NULL;
 }
 
+void ChromeNotifierDelegate::CollectAction(SyncedNotificationActionType type) {
+  DCHECK(!notification_id_.empty());
+
+  UMA_HISTOGRAM_ENUMERATION("SyncedNotifications.Actions",
+                            type,
+                            SYNCED_NOTIFICATION_ACTION_COUNT);
+}
+
+
 // 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.
+  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.
+  CollectAction(SYNCED_NOTIFICATION_ACTION_BUTTON_CLICK);

[Alexei Svitkine (slow), 2013/10/18 13:09:08]

Move this into the if above (to be consistent with the function above that does
an early return when the notification isn't found. (Alternatively, change
Click() to match this code structure instead - either way make them consistent.)

 }
 
 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_);
+
+  CollectAction(by_user ?
+      SYNCED_NOTIFICATION_ACTION_CLOSE_BY_USER :
+      SYNCED_NOTIFICATION_ACTION_CLOSE_BY_SYSTEM);
 }
 
 }  // namespace notifier