Bug 774220 - Script URLs should appear in tooltips even when the menu list is not open; r=past

browser/devtools/debugger/debugger-view.js

@@ -428,6 +428,7 @@ ScriptsView.prototype = {
     }
 
     this._preferredScript = selectedItem;
+    this._scripts.setAttribute("tooltiptext", selectedItem.value);
     DebuggerController.SourceScripts.showScript(selectedItem.getUserData("sourceScript"));
   },