<firebase-auth> does allow access to Google REST APIs through <iron-ajax>

[dwberry]

Description

Sign in with Google through firebase-auth will not allow access to google REST APIs.

Expected outcome

Return JSON response from Google Rest

Actual outcome

Returns: 401 Login Required....

{
 "error": {
  "errors": [
   {
    "domain": "global",
    "reason": "required",
    "message": "Login Required",
    "locationType": "header",
    "location": "Authorization"
   }
  ],
  "code": 401,
  "message": "Login Required"
 }
}

Code

<link rel="import" href="../bower_components/polymer/polymer.html">
<link rel="import" href="../bower_components/polymerfire/polymerfire.html">
<link rel="import" href="../bower_components/iron-image/iron-image.html">
<link rel="import" href="../bower_components/iron-list/iron-list.html">
<link rel="import" href="../bower_components/google-apis/google-apis.html">
<link rel="import" href="../bower_components/iron-ajax/iron-ajax.html">

<link rel="import" href="shared-styles.html">

<dom-module id="doc-create">
  <template>
    <style include="shared-styles">
      :host {
        display: block;
        padding: 10px;
      }
    </style>
      <iron-ajax
        auto
        url="https://www.googleapis.com/drive/v3/about"
        params = "{{ajaxParams}}"
        handle-as="json"
        with-credentials
        last-response="{{ajaxResponse}}"></iron-ajax>
    <div class="card">
      <template is="dom-repeat" items="[[ajaxResponse]]">
        <div class="horizontal-section">
        <p>[[index]]: [[item.title]]</p>
        </div>
      </template>
    </div>
    <div class="card">
        Response Data: [[ajaxResponse]]
        Params: [[ajaxParams.fields]]
    </div>
  </template>
  <script>
    Polymer({
      is: 'doc-create',
      properties: {
          fields: {
              type: String,
              value: 'user'
          },
          apikey: {
              type: String,
              value: 'ya29.CjBVA-xVkMLL1f7j9bw....'
          },
          ajaxParams: {
              type: String,
              computed: 'processParams(fields, apikey)'
          }
      },
        processParams: function(fields, apikey) {
            return {
                fields: fields,
                key: apikey
            };
        }
    });
  </script>
</dom-module>

Steps to reproduce

Call to Firebase-auth with:

 signIn: function() {
          this.$.auth.signInWithPopup().then(function(result){
            var token = String(result.credential.accessToken);
            console.log(token);
            this.apitoken= token;
          });

Added scopes to Polymerfire/firebase-auth:
Line 248:

        _providerFromName: function(name) {
          switch (name) {
            case 'facebook': return new firebase.auth.FacebookAuthProvider();
            case 'github': return new firebase.auth.GithubAuthProvider();
            case 'google': {
              var provider = new firebase.auth.GoogleAuthProvider();
              provider.addScope('https://mail.google.com/');
              provider.addScope('https://www.googleapis.com/auth/drive');
            } return provider;
            case 'twitter': return new firebase.auth.TwitterAuthProvider();
            default: this.fire('error', 'Unrecognized firebase-auth provider "' + name + '"');
          }
        },

[mbleigh]

Duplicate of #103, see my comment here.