Google Oauth API Javascript ​Invalid cookiePolicy error

The following code works if it's served properly.

[html]

<script src="https://apis.google.com/js/api.js"></script>

<script>

  function authenticate() {

    return gapi.auth2.getAuthInstance()

        .signIn({scope: "https://www.googleapis.com/auth/yt-analytics.readonly"})

        .then(function() { console.log("Sign-in successful"); },

              function(err) { console.error("Error signing in", err); });

  }

  function loadClient() {

    return gapi.client.load("https://youtubeanalytics.googleapis.com/$discovery/rest?version=v2")

        .then(function() { console.log("GAPI client loaded for API"); },

              function(err) { console.error("Error loading GAPI client for API", err); });

  }

  // Make sure the client is loaded and sign-in is complete before calling this method.

  function execute() {

    return gapi.client.youtubeAnalytics.reports.query({

      "ids": "channel==MINE",

      "startDate": "2017-01-01",

      "endDate": "2017-12-31",

      "metrics": "views,estimatedMinutesWatched,averageViewDuration,averageViewPercentage,subscribersGained",

      "dimensions": "day",

      "sort": "day"

    })

        .then(function(response) {

                // Handle the results here (response.result has the parsed body).

                console.log("Response", response);

              },

              function(err) { console.error("Execute error", err); });

  }

  gapi.load("client:auth2", function() {

    gapi.auth2.init({client_id: 'Your_Client_ID_Here'});

  });

</script>

<button onclick="authenticate().then(loadClient)">authorize and load</button>

<button onclick="execute()">execute</button>

[/html]

The two errors I encountered: 

Invalid cookiePolicy error:

This error happens when the html file is NOT served from a HTTP server but opened directly as a file.

N

ot a valid origin for the client:

This error happens when a origin is not added to the client id whitelist. And I have to use HTTPS instead of HTTP to make it work.