Use the local user's email when connecting to It2MeHelpeeChannel

An It2Me connection requires an email for domain policy check.
We should use the email of the helpee instead of the helper.

Summary of changes:
1. Modifies it2meHelpeeChannel to fetch its token and the user's credentials
   using remoting.identity.
2. Implement the background page as an object to initialize remoting.identity
   appropriately.
3. Makes the consentDialog argument optional in remoting.identity as user
   consent is suggested as opposed to required in the chrome identity API.

BUG=454897

Review URL: https://codereview.chromium.org/896003002

Cr-Commit-Position: refs/heads/master@{#314651}

remoting/remoting_webapp_files.gypi

@@ -241,6 +241,7 @@
       'webapp/crd/js/hangout_consent_dialog.js',
       'webapp/crd/js/host_installer.js',
       'webapp/crd/js/host_session.js',
+      'webapp/crd/js/identity.js',
       'webapp/crd/js/it2me_helpee_channel.js',
       'webapp/crd/js/it2me_helper_channel.js',
       'webapp/crd/js/it2me_host_facade.js',

remoting/webapp/base/js/base.js

@@ -78,6 +78,7 @@ base.Disposables.prototype.dispose = function() {
   for (var i = 0; i < this.disposables_.length; i++) {
     this.disposables_[i].dispose();
   }
+  this.disposables_ = null;
 };
 
 /**

remoting/webapp/crd/js/background.js

@@ -9,45 +9,71 @@ var remoting = remoting || {};
 
 'use strict';
 
+var ENABLE_HANGOUT_REMOTE_ASSISTANCE = true;
+
 /**
- * The background service is responsible for listening to incoming connection
- * requests from Hangouts and the webapp.
- *
- * @param {remoting.AppLauncher} appLauncher
+ * @constructor
  */
-function initializeBackgroundService(appLauncher) {
-  function initializeIt2MeService() {
-    /** @type {remoting.It2MeService} */
-    remoting.it2meService = new remoting.It2MeService(appLauncher);
-    remoting.it2meService.init();
-  }
+var BackgroundPage = function() {
+  /** @private {remoting.AppLauncher} */
+  this.appLauncher_ = null;
+  /** @private {remoting.ActivationHandler} */
+  this.activationHandler_ = null;
+  /** @private {remoting.It2MeService} */
+  this.it2meService_ = null;
+  /** @private {base.Disposables} */
+  this.disposables_ = null;
 
-  chrome.runtime.onSuspend.addListener(function() {
-    base.debug.assert(remoting.it2meService != null);
-    remoting.it2meService.dispose();
-    remoting.it2meService = null;
-  });
+  this.preInit_();
+  this.onResumed_();
 
-  remoting.settings = new remoting.Settings();
+  chrome.runtime.onSuspendCanceled.addListener(this.onResumed_.bind(this));
+  chrome.runtime.onSuspend.addListener(this.onSuspended_.bind(this));
+};
 
-  chrome.runtime.onSuspendCanceled.addListener(initializeIt2MeService);
-  initializeIt2MeService();
-}
+/**
+ * Initialize members and globals that are valid throughout the entire lifetime
+ * of the background page.
+ *
+ * @private
+ */
+BackgroundPage.prototype.preInit_ = function() {
+  remoting.settings = new remoting.Settings();
+  if (base.isAppsV2()) {
+    remoting.identity = new remoting.Identity();
+  } else {
+    remoting.oauth2 = new remoting.OAuth2();
+    var oauth2 = /** @type {*} */ (remoting.oauth2);
+    remoting.identity = /** @type {remoting.Identity} */ (oauth2);
+  }
 
-function main() {
   if (base.isAppsV2()) {
-    new remoting.ActivationHandler(base.Ipc.getInstance(),
-                                   new remoting.V2AppLauncher());
+    this.appLauncher_ = new remoting.V2AppLauncher();
+    this.activationHandler_ = new remoting.ActivationHandler(
+        base.Ipc.getInstance(), this.appLauncher_);
+  } else {
+    this.appLauncher_ = new remoting.V1AppLauncher();
   }
-}
+};
+
+/** @private */
+BackgroundPage.prototype.onResumed_ = function() {
+  if (ENABLE_HANGOUT_REMOTE_ASSISTANCE) {
+    this.it2meService_ = new remoting.It2MeService(this.appLauncher_);
+    this.it2meService_.init();
+    this.disposables_ = new base.Disposables(this.it2meService_);
+  }
+};
 
-remoting.enableHangoutsRemoteAssistance = function() {
-  /** @type {remoting.AppLauncher} */
-  var appLauncher = base.isAppsV2() ? new remoting.V1AppLauncher():
-                                      new remoting.V2AppLauncher();
-  initializeBackgroundService(appLauncher);
+/** @private */
+BackgroundPage.prototype.onSuspended_ = function() {
+  this.it2meService_ = null;
+  base.dispose(this.disposables_);
+  this.disposables_ = null;
 };
 
-window.addEventListener('load', main, false);
+window.addEventListener('load', function() {
+  remoting.backgroundPage = new BackgroundPage();
+}, false);
 
 }());

remoting/webapp/crd/js/identity.js

@@ -21,12 +21,12 @@ var remoting = remoting || {};
 remoting.identity = null;
 
 /**
- * @param {remoting.Identity.ConsentDialog} consentDialog
+ * @param {remoting.Identity.ConsentDialog=} opt_consentDialog
  * @constructor
  */
-remoting.Identity = function(consentDialog) {
+remoting.Identity = function(opt_consentDialog) {
   /** @private */
-  this.consentDialog_ = consentDialog;
+  this.consentDialog_ = opt_consentDialog;
   /** @type {string} @private */
   this.email_ = '';
   /** @type {string} @private */
@@ -36,7 +36,7 @@ remoting.Identity = function(consentDialog) {
 };
 
 /**
- * chrome.identity.getAuthToken must be initiated from user interactions if
+ * chrome.identity.getAuthToken should be initiated from user interactions if
  * called with interactive equals true.  This interface prompts a dialog for
  * the user's consent.
  *
@@ -223,7 +223,9 @@ remoting.Identity.prototype.onAuthComplete_ = function(interactive, token) {
   // If there's no token, but we haven't yet prompted for permission, do so
   // now.
   var that = this;
-  this.consentDialog_.show().then(function() {
+  var showConsentDialog =
+      (this.consentDialog_) ? this.consentDialog_.show() : Promise.resolve();
+  showConsentDialog.then(function() {
     chrome.identity.getAuthToken({'interactive': true},
                                  that.onAuthComplete_.bind(that, true));
   });

remoting/webapp/crd/js/it2me_helpee_channel.js

@@ -249,33 +249,26 @@ remoting.It2MeHelpeeChannel.prototype.onHangoutDisconnect_ = function() {
  */
 remoting.It2MeHelpeeChannel.prototype.handleConnect_ =
     function(message) {
-  var email = getStringAttr(message, 'email');
   var bounds =
       /** @type {Bounds} */ (getObjectAttr(message, 'hangoutBounds', null));
 
-  if (!email) {
-    throw new Error('Missing required parameter: email');
-  }
-
   if (this.hostState_ !== remoting.HostSession.State.UNKNOWN) {
     throw new Error('An existing connection is in progress.');
   }
 
   var that = this;
-  this.showConfirmDialog_(bounds).then(
-    this.initializeHost_.bind(this)
-  ).then(
-    this.fetchOAuthToken_.bind(this)
-  ).then(
-    /** @type {function(*):void} */(this.connectToHost_.bind(this, email))
-  ).catch(
-    /** @param {*} reason */
-    function(reason) {
-      var error = /** @type {Error} */ (reason);
-      that.sendErrorResponse_(message, error);
-      that.dispose();
-    }
-  );
+  this.showConfirmDialog_(bounds)
+      .then(this.initializeHost_.bind(this))
+      .then(this.fetchOAuthToken_.bind(this))
+      .then(this.fetchEmail_.bind(this))
+      /** @param {{email:string, token:string}|Promise} result */
+      .then(function(result) {
+        that.connectToHost_(result.email, result.token);
+      /** @param {*} reason */
+      }).catch(function(reason) {
+        that.sendErrorResponse_(message, /** @type {Error} */ (reason));
+        that.dispose();
+      });
 };
 
 /**
@@ -368,9 +361,10 @@ remoting.It2MeHelpeeChannel.prototype.fetchOAuthToken_ = function() {
   if (base.isAppsV2()) {
     /**
      * @param {function(*=):void} resolve
+     * @param {function(*=):void} reject
      */
-    return new Promise(function(resolve){
-      chrome.identity.getAuthToken({'interactive': true}, resolve);
+    return new Promise(function(resolve, reject){
+      remoting.identity.callWithToken(resolve, reject);
     });
   } else {
     /**
@@ -378,23 +372,40 @@ remoting.It2MeHelpeeChannel.prototype.fetchOAuthToken_ = function() {
      * @param {function(*=):void} reject
      */
     return new Promise(function(resolve, reject) {
-      /** @type {remoting.OAuth2} */
-      var oauth2 = new remoting.OAuth2();
       /** @param {remoting.Error} error */
       var onError = function(error) {
         if (error === remoting.Error.NOT_AUTHENTICATED) {
-          oauth2.doAuthRedirect(function() {
-            oauth2.callWithToken(resolve, reject);
+          remoting.oauth2.doAuthRedirect(function() {
+            remoting.identity.callWithToken(resolve, reject);
           });
           return;
         }
         reject(new Error(remoting.Error.NOT_AUTHENTICATED));
       };
-      oauth2.callWithToken(resolve, onError);
+      remoting.identity.callWithToken(resolve, onError);
     });
   }
 };
 
+/**
+ * @param {string|Promise} token
+ * @return {Promise} Promise that resolves with the access token and the email
+ *   of the user.
+ */
+remoting.It2MeHelpeeChannel.prototype.fetchEmail_ = function(token) {
+  /**
+   * @param {function(*=):void} resolve
+   * @param {function(*=):void} reject
+   */
+  return new Promise(function(resolve, reject){
+    /** @param {string} email */
+    function onEmail (email) {
+      resolve({ email: email, token: token });
+    }
+    remoting.identity.getEmail(onEmail, reject);
+  });
+};
+
 /**
  * Connects to the It2Me Native Messaging Host and retrieves the access code
  * in the |onHostStateChanged_| callback.

remoting/webapp/crd/js/it2me_service.js

@@ -16,7 +16,9 @@ var remoting = remoting || {};
 
 /**
  * @param {remoting.AppLauncher} appLauncher
+ *
  * @constructor
+ * @implements {base.Disposable}
  */
 remoting.It2MeService = function(appLauncher) {
   /**

remoting/webapp/unittests/it2me_helpee_channel_unittest.js

@@ -47,6 +47,11 @@ module('It2MeHelpeeChannel', {
 
     // remoting.settings
     remoting.settings = new remoting.Settings();
+    remoting.identity = new remoting.Identity();
+  },
+  tearDown: function() {
+    remoting.settings = null;
+    remoting.identity = null;
   }
 });
 
@@ -112,19 +117,6 @@ test('downloadHost() should trigger a host download',
   sinon.assert.called(hostInstaller.download);
 });
 
-test('connect() should return error if email is missing',
-    function() {
-  var MessageTypes = remoting.It2MeHelpeeChannel.HangoutMessageTypes;
-
-  hangoutPort.onMessage.mock$fire({
-    method: MessageTypes.CONNECT
-  });
-
-  sinon.assert.calledWithMatch(hangoutPort.postMessage, {
-      method: MessageTypes.ERROR
-  });
-});
-
 QUnit.asyncTest('connect() should return access code',
     function() {
   // Stubs authentication.
@@ -136,6 +128,10 @@ QUnit.asyncTest('connect() should return access code',
   });
   sinon.stub(chrome.identity, 'getAuthToken')
       .callsArgWith(1, 'token');
+  sinon.stub(remoting.identity, 'callWithToken')
+      .callsArgWith(0, 'token');
+  sinon.stub(remoting.identity, 'getEmail')
+      .callsArgWith(0, {token: 'token', email: 'test@chromium.org'});
   // Stubs Host behavior.
   sinon.stub(host, 'initialized').returns(true);
   sinon.stub(host, 'connect')
@@ -145,7 +141,6 @@ QUnit.asyncTest('connect() should return access code',
   var MessageTypes = remoting.It2MeHelpeeChannel.HangoutMessageTypes;
   hangoutPort.onMessage.mock$fire({
     method: MessageTypes.CONNECT,
-    email: 'test@chromium.org',
     hangoutBounds: {widht: 10, height: 10, left:10, top: 10}
   });