Implementation of the "Redirect URLs to Packaged Apps" feature.

chrome/common/extensions/api/app_runtime.idl

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 namespace app.runtime {
 
   [inline_doc] dictionary LaunchItem {
     // FileEntry for the file.
     [instanceOf=FileEntry] object entry;
 
     // The MIME type of the file.
     DOMString type;
   };
 
   // Optional data for the launch.
   [inline_doc] dictionary LaunchData {
-    // The id of the file handler that the app is being invoked with.
+    // The ID of the file or URL handler that the app is being invoked with.
+    // Handler IDs are the top-level keys in the <code>file_handlers</code>
+    // and/or <code>url_handlers</code> dictionaries in the manifest.
     DOMString? id;
 
+    // The file entries for <code>onLaunched</code> triggered by a matching
+    // file handler from the <code>file_handlers</code> manifest key.
     LaunchItem[]? items;
+
+    // The URL for <code>onLaunched</code> triggered by a matching URL handler
+    // from the <code>url_handlers</code> manifest key.

[benwells, 2013/08/30 05:41:39]

Can you foresee a need to send through multiple URLs with one launch event? ...
I don't like the asymmetry of file handlers having an array and url handlers not
but I can see that an array is probably not needed.

[sergeygs, 2013/09/02 07:36:22]

I really do not foresee such a need, at least not with the currently expected
usage.

+    DOMString? url;
+
+    // The referrer URL for <code>onLaunched</code> triggered by a matching
+    // URL handler from the <code>url_handlers</code> manifest key.
+    DOMString? referrerUrl;
   };
 
   interface Events {
     // Fired when an app is launched from the launcher.
     static void onLaunched(optional LaunchData launchData);
 
     // Fired at Chrome startup to apps that were running when Chrome last shut
     // down.
     static void onRestarted();
   };
 };