[Download Notification] Clean Up: Initialize properties in header file

chrome/browser/download/notification/download_notification_item.h

Index: chrome/browser/download/notification/download_notification_item.h
diff --git a/chrome/browser/download/notification/download_notification_item.h b/chrome/browser/download/notification/download_notification_item.h
index ab51542f7b6cffdaeb3bbd95b43fa231e1436f82..361243791a8e277db53720721612beecf87b1480 100644
--- a/chrome/browser/download/notification/download_notification_item.h
+++ b/chrome/browser/download/notification/download_notification_item.h
@@ -101,17 +101,14 @@ class DownloadNotificationItem : public content::DownloadItem::Observer {
 
   scoped_ptr<std::vector<DownloadCommands::Command>> GetPossibleActions() const;
 
-  bool openable_;
-  bool downloading_;
-  int image_resource_id_;
+  bool openable_ = false;
+  bool downloading_ = false;
+  int image_resource_id_ = 0;
   Profile* profile_;
   scoped_refptr<NotificationWatcher> watcher_;
-
   scoped_ptr<Notification> notification_;
-
   content::DownloadItem* item_;
   scoped_ptr<std::vector<DownloadCommands::Command>> button_actions_;
-
   Delegate* const delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadNotificationItem);