cros: Use webview.addContentScripts for new Gaia SAML.

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 553 matching lines @@
                             password: this.password_ || '',
                             authCode: this.oauth_code_,
                             usingSAML: this.authFlow == AuthFlow.SAML,
                             chooseWhatToSync: this.chooseWhatToSync_,
                             skipForNow: this.skipForNow_,
                             sessionIndex: this.sessionIndex_ || '',
                             trusted: this.trusted_,
                             deviceId: this.deviceId_ || ''
                           }
                         }));
+    this.clearCredentials_();
   };
 
   /**
    * Invoked when |samlHandler_| fires 'insecureContentBlocked' event.
    * @private
    */
   Authenticator.prototype.onInsecureContentBlocked_ = function(e) {
     if (this.insecureContentBlockedCallback) {
       this.insecureContentBlockedCallback(e.detail.url);
     } else {
@@ skipping 162 matching lines @@
   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,
     Authenticator: Authenticator
   };
 });