Bug 663347 Give popup notification panels role="alert" and make their close buttons tabbable. r=Neil ui-r=Neil

suite/browser/navigator.xul

@@ -170,7 +170,11 @@
     <!-- Bookmarks and history tooltip -->
     <tooltip id="bhTooltip"/>
 
-    <panel id="notification-popup" type="arrow" position="after_start" hidden="true"/>
+    <panel id="notification-popup"
+           type="arrow"
+           position="after_start"
+           hidden="true"
+           role="alert"/>
 
     <menupopup id="popupBlockerMenu"
                oncommand="popupBlockerMenuCommand(event.target);"

suite/common/bindings/notification.xml

@@ -2421,7 +2421,7 @@
       </xul:vbox>
       <xul:vbox pack="start">
         <xul:toolbarbutton anonid="closebutton"
-                           class="messageCloseButton popup-notification-closebutton"
+                           class="messageCloseButton popup-notification-closebutton tabbable"
                            xbl:inherits="oncommand=closebuttoncommand"
                            tooltiptext="&closeNotification.tooltip;"/>
       </xul:vbox>
@@ -2464,7 +2464,7 @@
       </xul:vbox>
       <xul:vbox pack="start">
         <xul:toolbarbutton anonid="closebutton"
-                           class="messageCloseButton popup-notification-closebutton"
+                           class="messageCloseButton popup-notification-closebutton tabbable"
                            xbl:inherits="oncommand=closebuttoncommand"
                            tooltiptext="&closeNotification.tooltip;"/>
       </xul:vbox>