Ash Tray: Add Notifications.Cros.Actions.Tray.ExpireToTray histogram.

This metric is logged whenever a notification popup times out and exipres to the
tray. This CL also implements a new observer function for this event.

BUG=1050809

Change-Id: Id45954d668637222a59062f8c022ba343fb8d1b3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2040919
Reviewed-by: Ahmed Mehfooz <amehfooz@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Commit-Queue: Tim Song <tengs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#741321}

ash/system/message_center/message_center_ui_controller.cc

@@ -147,6 +147,14 @@ void MessageCenterUiController::OnBlockingStateChanged(
   OnMessageCenterChanged();
 }
 
+void MessageCenterUiController::OnNotificationPopupShown(
+    const std::string& notification_id,
+    bool mark_notification_as_read) {
+  // Timed out popup notifications are not marked as read.
+  if (!mark_notification_as_read)
+    metrics_utils::LogPopupExpiredToTray(notification_id);
+}
+
 void MessageCenterUiController::OnMessageCenterChanged() {
   if (hide_on_last_notification_ && message_center_visible_ &&
       message_center_->NotificationCount() == 0) {

ash/system/message_center/message_center_ui_controller.h

@@ -76,6 +76,8 @@ class ASH_EXPORT MessageCenterUiController
   void OnQuietModeChanged(bool in_quiet_mode) override;
   void OnBlockingStateChanged(
       message_center::NotificationBlocker* blocker) override;
+  void OnNotificationPopupShown(const std::string& notification_id,
+                                bool mark_notification_as_read) override;
 
  private:
   void OnMessageCenterChanged();

ash/system/message_center/metrics_utils.cc

@@ -240,5 +240,14 @@ void LogClickedActionButton(const std::string& notification_id, bool is_popup) {
   }
 }
 
+void LogPopupExpiredToTray(const std::string& notification_id) {
+  auto type = GetNotificationType(notification_id);
+  if (!type.has_value())
+    return;
+
+  UMA_HISTOGRAM_ENUMERATION("Notifications.Cros.Actions.Popup.ExpireToTray",
+                            type.value());
+}
+
 }  // namespace metrics_utils
 }  // namespace ash

ash/system/message_center/metrics_utils.h

@@ -69,6 +69,9 @@ void LogClickedBody(const std::string& notification_id, bool is_popup);
 // Logs a ClickedActionButton event.
 void LogClickedActionButton(const std::string& notification_id, bool is_popup);
 
+// Logs a ExpireToTray event for a pop-up notification.
+void LogPopupExpiredToTray(const std::string& notification_id);
+
 }  // namespace metrics_utils
 
 }  // namespace ash

tools/metrics/histograms/histograms.xml

@@ -182029,6 +182029,7 @@ regressions. -->
   <owner>gzadina@google.com</owner>
   <suffix name="Popup.ClickedActionButton" label=""/>
   <suffix name="Popup.ClickedBody" label=""/>
+  <suffix name="Popup.ExpireToTray" label=""/>
   <suffix name="Tray.ClickedActionButton" label=""/>
   <suffix name="Tray.ClickedBody" label=""/>
   <affected-histogram name="Notifications.Cros.Actions"/>

ui/message_center/message_center_impl.cc

@@ -411,8 +411,10 @@ void MessageCenterImpl::MarkSinglePopupAsShown(const std::string& id,
 
   if (HasMessageCenterView()) {
     notification_list_->MarkSinglePopupAsShown(id, mark_notification_as_read);
-    for (auto& observer : observer_list_)
+    for (auto& observer : observer_list_) {
       observer.OnNotificationUpdated(id);
+      observer.OnNotificationPopupShown(id, mark_notification_as_read);
+    }
   } else {
     RemoveNotification(id, false);
   }

ui/message_center/message_center_observer.h

@@ -62,6 +62,11 @@ class MESSAGE_CENTER_EXPORT MessageCenterObserver {
 
   // Called when the blocking state of |blocker| is changed.
   virtual void OnBlockingStateChanged(NotificationBlocker* blocker) {}
+
+  // Called after a visible notification popup closes, indicating it has been
+  // shown to the user, and whether the notification is marked as read.
+  virtual void OnNotificationPopupShown(const std::string& notification_id,
+                                        bool mark_notification_as_read) {}
 };
 
 }  // namespace message_center