Updated XHR API so call sites are more descriptive.

remoting/webapp/crd/js/oauth2_api_impl.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.
 
 /**
  * @fileoverview
  * OAuth2 API flow implementations.
  */
 
 'use strict';
@@ skipping 55 matching lines @@
  *     the access token and expiration time are successfully fetched.
  * @param {function(!remoting.Error):void} onError Callback invoked if an
  *     error occurs.
  * @param {string} clientId OAuth2 client ID.
  * @param {string} clientSecret OAuth2 client secret.
  * @param {string} refreshToken OAuth2 refresh token to be redeemed.
  * @return {void} Nothing.
  */
 remoting.OAuth2ApiImpl.prototype.refreshAccessToken = function(
     onDone, onError, clientId, clientSecret, refreshToken) {
-  /** @param {XMLHttpRequest} xhr */
-  var onResponse = function(xhr) {
-    if (xhr.status == 200) {
+  /** @param {remoting.Xhr.Response} xhrr */
+  var onResponse = function(xhrr) {
+    if (xhrr.status == 200) {
       try {
         // Don't use base.jsonParseSafe here unless you also include base.js,
         // otherwise this won't work from the OAuth trampoline.
         // TODO(jamiewalch): Fix this once we're no longer using the trampoline.
-        var tokens = JSON.parse(xhr.responseText);
+        var tokens = JSON.parse(xhrr.responseText);
         onDone(tokens['access_token'], tokens['expires_in']);
       } catch (/** @type {Error} */ err) {
         console.error('Invalid "token" response from server:', err);
         onError(remoting.Error.UNEXPECTED);
       }
     } else {
-      console.error('Failed to refresh token. Status: ' + xhr.status +
-                    ' response: ' + xhr.responseText);
-      onError(remoting.Error.fromHttpStatus(xhr.status));
+      console.error('Failed to refresh token. Status: ' + xhrr.status +
+                    ' response: ' + xhrr.responseText);
+      onError(remoting.Error.fromHttpStatus(xhrr.status));
     }
   };
 
-  remoting.xhr.start({
+  new remoting.Xhr({
     method: 'POST',
     url: this.getOAuth2TokenEndpoint_(),
-    onDone: onResponse,
     formContent: {
       'client_id': clientId,
       'client_secret': clientSecret,
       'refresh_token': refreshToken,
       'grant_type': 'refresh_token'
     }
-  });
+  }).then(onResponse);
 };
 
 /**
  * Asynchronously exchanges an authorization code for access and refresh tokens.
  *
  * @param {function(string, string, number): void} onDone Callback to
  *     invoke when the refresh token, access token and access token expiration
  *     time are successfully fetched.
  * @param {function(!remoting.Error):void} onError Callback invoked if an
  *     error occurs.
  * @param {string} clientId OAuth2 client ID.
  * @param {string} clientSecret OAuth2 client secret.
  * @param {string} code OAuth2 authorization code.
  * @param {string} redirectUri Redirect URI used to obtain this code.
  * @return {void} Nothing.
  */
 remoting.OAuth2ApiImpl.prototype.exchangeCodeForTokens = function(
     onDone, onError, clientId, clientSecret, code, redirectUri) {
-  /** @param {XMLHttpRequest} xhr */
-  var onResponse = function(xhr) {
-    if (xhr.status == 200) {
+  /** @param {remoting.Xhr.Response} xhrr */
+  var onResponse = function(xhrr) {
+    if (xhrr.status == 200) {
       try {
         // Don't use base.jsonParseSafe here unless you also include base.js,
         // otherwise this won't work from the OAuth trampoline.
         // TODO(jamiewalch): Fix this once we're no longer using the trampoline.
-        var tokens = JSON.parse(xhr.responseText);
+        var tokens = JSON.parse(xhrr.responseText);
         onDone(tokens['refresh_token'],
                tokens['access_token'], tokens['expires_in']);
       } catch (/** @type {Error} */ err) {
         console.error('Invalid "token" response from server:', err);
         onError(remoting.Error.UNEXPECTED);
       }
     } else {
-      console.error('Failed to exchange code for token. Status: ' + xhr.status +
-                    ' response: ' + xhr.responseText);
-      onError(remoting.Error.fromHttpStatus(xhr.status));
+      console.error('Failed to exchange code for token. Status: ' +
+                    xhrr.status + ' response: ' + xhrr.responseText);
+      onError(remoting.Error.fromHttpStatus(xhrr.status));
     }
   };
 
-  remoting.xhr.start({
+  new remoting.Xhr({
     method: 'POST',
     url: this.getOAuth2TokenEndpoint_(),
-    onDone: onResponse,
     formContent: {
       'client_id': clientId,
       'client_secret': clientSecret,
       'redirect_uri': redirectUri,
       'code': code,
       'grant_type': 'authorization_code'
     }
-  });
+  }).then(onResponse);
 };
 
 /**
  * Get the user's email address.
  *
  * @param {function(string):void} onDone Callback invoked when the email
  *     address is available.
  * @param {function(!remoting.Error):void} onError Callback invoked if an
  *     error occurs.
  * @param {string} token Access token.
  * @return {void} Nothing.
  */
 remoting.OAuth2ApiImpl.prototype.getEmail = function(onDone, onError, token) {
-  /** @param {XMLHttpRequest} xhr */
-  var onResponse = function(xhr) {
-    if (xhr.status == 200) {
+  /** @param {remoting.Xhr.Response} xhrr */
+  var onResponse = function(xhrr) {
+    if (xhrr.status == 200) {
       try {
-        var result = JSON.parse(xhr.responseText);
+        var result = JSON.parse(xhrr.responseText);
         onDone(result['email']);
       } catch (/** @type {Error} */ err) {
         console.error('Invalid "userinfo" response from server:', err);
         onError(remoting.Error.UNEXPECTED);
       }
     } else {
-      console.error('Failed to get email. Status: ' + xhr.status +
-                    ' response: ' + xhr.responseText);
-      onError(remoting.Error.fromHttpStatus(xhr.status));
+      console.error('Failed to get email. Status: ' + xhrr.status +
+                    ' response: ' + xhrr.responseText);
+      onError(remoting.Error.fromHttpStatus(xhrr.status));
     }
   };
-  remoting.xhr.start({
+  new remoting.Xhr({
     method: 'GET',
     url: this.getOAuth2ApiUserInfoEndpoint_(),
-    onDone: onResponse,
     oauthToken: token
-  });
+  }).then(onResponse);
 };
 
 /**
  * Get the user's email address and full name.
  *
  * @param {function(string, string):void} onDone Callback invoked when the email
  *     address and full name are available.
  * @param {function(!remoting.Error):void} onError Callback invoked if an
  *     error occurs.
  * @param {string} token Access token.
  * @return {void} Nothing.
  */
 remoting.OAuth2ApiImpl.prototype.getUserInfo =
     function(onDone, onError, token) {
-  /** @param {XMLHttpRequest} xhr */
-  var onResponse = function(xhr) {
-    if (xhr.status == 200) {
+  /** @param {remoting.Xhr.Response} xhrr */
+  var onResponse = function(xhrr) {
+    if (xhrr.status == 200) {
       try {
-        var result = JSON.parse(xhr.responseText);
+        var result = JSON.parse(xhrr.responseText);
         onDone(result['email'], result['name']);
       } catch (/** @type {Error} */ err) {
         console.error('Invalid "userinfo" response from server:', err);
         onError(remoting.Error.UNEXPECTED);
       }
     } else {
-      console.error('Failed to get user info. Status: ' + xhr.status +
-                    ' response: ' + xhr.responseText);
-      onError(remoting.Error.fromHttpStatus(xhr.status));
+      console.error('Failed to get user info. Status: ' + xhrr.status +
+                    ' response: ' + xhrr.responseText);
+      onError(remoting.Error.fromHttpStatus(xhrr.status));
     }
   };
-  remoting.xhr.start({
+  new remoting.Xhr({
     method: 'GET',
     url: this.getOAuth2ApiUserInfoEndpoint_(),
-    onDone: onResponse,
     oauthToken: token
-  });
+  }).then(onResponse);
 };
 
 /** @type {remoting.OAuth2Api} */
 remoting.oauth2Api = new remoting.OAuth2ApiImpl();