Bug 1047977 - Invert the notification bar close icon with @type=info on OS X to provide contrast. r=Gijs

--HG--
extra : rebase_source : d011aab37113d6e58c0df8e155d871600f54d514

toolkit/themes/osx/global/notification.css

@@ -68,6 +68,20 @@ notification[type="critical"] {
   border: none;
 }
 
+/*
+ Invert the close icon for @type=info since both are normally dark. It's unclear
+ why !important is necessary here so remove it if it's no longer needed.
+*/
+notification[type="info"]:not([value="translation"]) .close-icon:not(:hover) {
+  -moz-image-region: rect(0, 64px, 16px, 48px) !important;
+}
+
+@media (min-resolution: 2dppx) {
+  notification[type="info"]:not([value="translation"]) .close-icon:not(:hover) {
+    -moz-image-region: rect(0, 128px, 32px, 96px) !important;
+  }
+}
+
 .messageCloseButton:-moz-focusring > .toolbarbutton-icon {
   border-radius: 10000px;
   box-shadow: 0 0 2px 1px -moz-mac-focusring,