Back button for the WebView-based sign-in flow.

chrome/browser/resources/gaia_auth_host/authenticator.js

 // 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.
 
 <include src="saml_handler.js">
 
 /**
  * @fileoverview An UI component to authenciate to Chrome. The component hosts
  * IdP web pages in a webview. A client who is interested in monitoring
  * authentication events should pass a listener object of type
@@ skipping 338 matching lines @@
 
     var msg = e.data;
     if (msg.method == 'attemptLogin') {
       this.email_ = msg.email;
       this.password_ = msg.password;
       this.chooseWhatToSync_ = msg.chooseWhatToSync;
     } else if (msg.method == 'dialogShown') {
       this.dispatchEvent(new Event('dialogShown'));
     } else if (msg.method == 'dialogHidden') {
       this.dispatchEvent(new Event('dialogHidden'));
+    } else if (msg.method == 'backButton') {
+      this.dispatchEvent(new CustomEvent('backButton', {detail: msg.show}));
     } else {
-      console.warning('Unrecognized message from GAIA: ' + msg.method);
+      console.warn('Unrecognized message from GAIA: ' + msg.method);
     }
   };
 
   /**
    * Invoked by the hosting page to verify the Saml password.
    */
   Authenticator.prototype.verifyConfirmedPassword = function(password) {
     if (!this.samlHandler_.verifyConfirmedPassword(password)) {
       // Invoke confirm password callback asynchronously because the
       // verification was based on messages and caller (GaiaSigninScreen)
@@ skipping 168 matching lines @@
   Authenticator.AuthFlow = AuthFlow;
   Authenticator.AuthMode = AuthMode;
   Authenticator.SUPPORTED_PARAMS = SUPPORTED_PARAMS;
 
   return {
     // TODO(guohui, xiyuan): Rename GaiaAuthHost to Authenticator once the old
     // iframe-based flow is deprecated.
     GaiaAuthHost: Authenticator
   };
 });