Adds functionality to pack an extension / app from the app.

chrome/browser/resources/apps_debugger/js/items.js

Index: chrome/browser/resources/apps_debugger/js/items.js
diff --git a/chrome/browser/resources/apps_debugger/js/items.js b/chrome/browser/resources/apps_debugger/js/items.js
index 3ec23a4fc679293cc9b769f553a0e05668a04bd5..47de213a99f06734df67bfb4f90aa63ddcc57baa 100644
--- a/chrome/browser/resources/apps_debugger/js/items.js
+++ b/chrome/browser/resources/apps_debugger/js/items.js
@@ -109,6 +109,8 @@ AppsDebugger.prototype = {
     $('update-items-now').addEventListener('click',
         this.handleUpdateItemNow_.bind(this));
 
+    var packItemOverlay = extensions.PackItemOverlay.getInstance();
+    packItemOverlay.initializePage();
   },
 
   /** Handles the Load Unpacked Extension button.
@@ -126,8 +128,7 @@ AppsDebugger.prototype = {
    * @private
    */
   handlePackItem_: function(e) {
-    //TODO (grv) : implement pack item.
-    console.log('yet to be implemented...');
+    AppsDebugger.showOverlay($('packItemOverlay'));
   },
 
   /**