Identity API: Add component app for auth flow UI

chrome/browser/resources/identity_scope_approval_dialog/background.js

+// Copyright 2013 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.
+
+/**
+ * Displays a webview based authorization dialog.
+ * @param {string} key A unique identifier that the caller can use to locate
+ *     the dialog window.
+ * @param {string} url A URL that will be loaded in the webview.
+ * @param {string} mode 'interactive' or 'silent'. The window will be displayed
+ *     if the mode is 'interactive'.
+ */
+function showAuthDialog(key, url, mode) {
+  var options = {
+    frame: 'none',
+    id: key,
+    minWidth: 1024,
+    minHeight: 768,
+    hidden: true
+  };
+  chrome.app.window.create('scope_approval_dialog.html',
+                           options,
+                           function(win) {
+    win.contentWindow.addEventListener('load', function(event) {
+      var windowParam;
+      if (mode == 'interactive')
+        windowParam = win;
+      win.contentWindow.loadAuthUrlAndShowWindow(url, windowParam);
+    });
+  });
+}
+
+chrome.identityPrivate.onWebFlowRequest.addListener(showAuthDialog);
+