Support creating progress bar notification for Windows

ui/message_center/notification.cc

Index: ui/message_center/notification.cc
diff --git a/ui/message_center/notification.cc b/ui/message_center/notification.cc
index e70563a0bab6e024238ab9e6a11e01ddabc5866c..a3530a53e19fba318e53b135cb6822ee1d77b3a2 100644
--- a/ui/message_center/notification.cc
+++ b/ui/message_center/notification.cc
@@ -26,7 +26,8 @@ ButtonInfo::ButtonInfo(const string16& title)
 RichNotificationData::RichNotificationData()
     : priority(DEFAULT_PRIORITY),
       never_timeout(false),
-      timestamp(base::Time::Now()) {}
+      timestamp(base::Time::Now()),
+      progress(0) {}
 
 RichNotificationData::RichNotificationData(const RichNotificationData& other)
     : priority(other.priority),
@@ -35,6 +36,7 @@ RichNotificationData::RichNotificationData(const RichNotificationData& other)
       expanded_message(other.expanded_message),
       image(other.image),
       items(other.items),
+      progress(other.progress),
       buttons(other.buttons) {}
 
 RichNotificationData::~RichNotificationData() {}