Make "source" a required argument of AppLaunchParams and fill in the argument in all call points.

extensions/common/api/app_runtime.idl

 // Copyright 2014 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.
 
 // Use the <code>chrome.app.runtime</code> API to manage the app lifecycle.
 // The app runtime manages app installation, controls the event page, and can
 // shut down the app at anytime.
 namespace app.runtime {
 
   [inline_doc] dictionary LaunchItem {
     // FileEntry for the file.
     [instanceOf=FileEntry] object entry;
 
     // The MIME type of the file.
     DOMString type;
   };
 
   // Enumeration of app launch sources.
   enum LaunchSource {
     app_launcher,
     new_tab_page,
     reload,
     restart,
     load_and_launch,
     command_line,
     file_handler,
     url_handler,
-
     system_tray,
     about_page,
-    keyboard
+    keyboard,
+    extensions_page,
+    management_api,
+    ephemeral_app,
+    background,
+    kiosk,
+    chrome_internal
   };
 
   // Optional data for the launch. Either <code>items</code>, or
   // the pair (<code>url, referrerUrl</code>) can be present for any given
   // launch.
   [inline_doc] dictionary LaunchData {
     // 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;
@@ skipping 45 matching lines @@
     static void onEmbedRequested(EmbedRequest request);
 
     // 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();
   };
 };