Add priority to Notification & NotificationOptions.

public/platform/modules/notifications/WebNotificationData.h

Index: public/platform/modules/notifications/WebNotificationData.h
diff --git a/public/platform/modules/notifications/WebNotificationData.h b/public/platform/modules/notifications/WebNotificationData.h
index 76b40f2f7b519d614996d63b57d6b7b1b6a4ec59..6bc002f6a7d1677832b945dd0506505f49d23b38 100644
--- a/public/platform/modules/notifications/WebNotificationData.h
+++ b/public/platform/modules/notifications/WebNotificationData.h
@@ -19,8 +19,17 @@ struct WebNotificationData {
         DirectionRightToLeft
     };
 
+    enum Priority {
+        PriorityLowest,
+        PriorityLow,
+        PriorityNormal,
+        PriorityHigh,
+        PriorityHighest
+    };
+
     WebNotificationData()
         : direction(DirectionLeftToRight)
+        , priority(PriorityNormal)
         , silent(false)
     {
     }
@@ -32,6 +41,7 @@ struct WebNotificationData {
         , lang(lang)
         , body(body)
         , tag(tag)
+        , priority(PriorityNormal)
         , icon(icon)
         , vibrate(vibrate)
         , silent(silent)
@@ -39,12 +49,29 @@ struct WebNotificationData {
     {
     }
 
+    // TODO(johnme): Remove this constructor when Chromium has switched to the new one.
     WebNotificationData(const WebString& title, Direction direction, const WebString& lang, const WebString& body, const WebString& tag, const WebURL& icon, const WebVector<int>& vibrate, bool silent, const WebVector<char>& data, const WebVector<WebNotificationAction>& actions)
         : title(title)
         , direction(direction)
         , lang(lang)
         , body(body)
         , tag(tag)
+        , priority(PriorityNormal)
+        , icon(icon)
+        , vibrate(vibrate)
+        , silent(silent)
+        , data(data)
+        , actions(actions)
+    {
+    }
+
+    WebNotificationData(const WebString& title, Direction direction, const WebString& lang, const WebString& body, const WebString& tag, Priority priority, const WebURL& icon, const WebVector<int>& vibrate, bool silent, const WebVector<char>& data, const WebVector<WebNotificationAction>& actions)
+        : title(title)
+        , direction(direction)
+        , lang(lang)
+        , body(body)
+        , tag(tag)
+        , priority(priority)
         , icon(icon)
         , vibrate(vibrate)
         , silent(silent)
@@ -58,6 +85,7 @@ struct WebNotificationData {
     WebString lang;
     WebString body;
     WebString tag;
+    Priority priority;
     WebURL icon;
     WebVector<int> vibrate;
     bool silent;