Keep receiving Login Required error when trying to upload a file to Google Drive
<p>I am writing a chrome extension that will intercept certain downloads (currently .doc and .docx files) and instead take those files and automatically upload them to your Google driver folder. Here is my manifest:</p>

<pre><code>{
    // Default manifest crap.
    "manifest_version": 2,
    "name": "App",
    "description": "SpartaHack 2016 application",
    "version": "1.0",
    "browser_action": {
        "default_icon": "icon.png",
        "default_popup": "popup.html"
    },
    // Content security needed to access gapi script.
    "content_security_policy": "script-src 'self' https://apis.google.com; object-src 'self'",
    // Need to view downloads, and identity for obvious reasons.
    // The other two permissions allow the script to access files that are outside our domain. 
    "permissions": [
        "downloads",
        "identity",
        "http://*/",
        "https://*/"
    ],
    // Gives us the auth information.
    "oauth2": {
        "client_id": "id",
        "scopes": [
            "https://www.googleapis.com/auth/drive.file",
            "https://www.googleapis.com/auth/userinfo.profile"
        ]
    },
    // Scripts that are always running.
    // Client.js has the gapi script, eventPage is our code.
    "background": {
        "scripts": ["client.js", "eventPage.js"]
    }
}
</code></pre>

<p>I have also written the following method that preforms authorization, if needed:</p>

<pre><code>chrome.identity.getAuthToken({
    "interactive": true
}, sendAuthToken);

function sendAuthToken(token) {
    var xhr = new XMLHttpRequest();
    xhr.open('GET', 'https://www.googleapis.com/oauth2/v1/userinfo?alt=json&amp;access_token=' + token, true);
    xhr.onload = function() {
        console.log(xhr.response);
    }

    //TODO: 
    xhr.send();
    console.log(token);
    watchDownloads();
}
</code></pre>

<p>This snippet I found from an example somewhere. It seemed it wasn't enough to just preform authorization, but that I had to send a request for the user's information using this token as well. This part doesn't give me any trouble - the token is logged fine, and the response that is logged shows all of my information as expected.</p>

<p>Here is what watchDownloads() looks like:</p>

<pre><code>function watchDownloads() {
    chrome.downloads.onCreated.addListener(function(download) {
        if(download.url.endsWith(".doc") || download.url.endsWith(".docx")) {
            // Get blob from URL
            var xhr = new XMLHttpRequest();
            xhr.open("GET", download.url, true);
            xhr.responseType = "blob";

            xhr.onload = function(error) {
                if(this.status == 200) {
                    insertFile(this.response, function(resp) {
                        console.log(resp);
                    });
                }
            };

            xhr.send();
        }
    });
}
</code></pre>

<p>In short, it looks for the two file extensions I am concerned with, and if it sees them it should then get that file using another HTTP request directly to the file's url, and then upload it into drive for us using this method, which has been mostly pieced together from online samples:</p>

<pre><code>function insertFile(fileData, callback) {
    const boundary = "-------314159265358979323846";
    const delimiter = "\r\n--" + boundary + "\r\n";
    const close_delimiter = "\r\n--" + boundary + "--";

    //TODO: Remove
    console.log(fileData);

    var reader = new FileReader();
    reader.readAsBinaryString(fileData);
    reader.onload = function(error) {
        var contentType = fileData.type || "application/octet-stream";
        var metadata = {
            // "title": fileData.filename,
            "title": "Potato",
            "mimeType": contentType
        };

        var base64Data = btoa(reader.result);
        var multipartRequestBody =
            delimiter +
            "Content-Type: application/json\r\n\r\n" +
            JSON.stringify(metadata) +
            delimiter +
            "Content-Type: " + contentType + "\r\n" +
            "Content-Transfer-Encoding: base64\r\n\r\n" +
            base64Data +
            close_delimiter;

        //TODO: Remove
        console.log(multipartRequestBody);

        var request = gapi.client.request({
            "path": "/upload/drive/v3/files",
            "method": "POST",
            "params": {
                "key": "key",
                "uploadType": "multipart"
            },
            "headers": {
                "Content-Type": 'multipart/mixed; boundary="' + boundary + '"'
            },
            "body": multipartRequestBody
        });

        //TODO: Remove
        console.log(request);

        if(!callback) {
            callback = function(file) {
                console.log(file)
            };
        }

        request.execute(callback);
    }
}
</code></pre>

<p>This is where it fails. I can't seem to get this to work, as the following error appears each time:</p>

<p><a href="https://i.stack.imgur.com/Rh0dj.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Rh0dj.png" alt="enter image description here"></a></p>

<p>What do I have to do to have the proper login here? I have tried adding an <code>Authorization</code> property in the header, but get the same error.</p>