Userscript for making it show titles on Arxiv pdfs.

arxiv-title.user.js

// ==UserScript==
// @name        Arxiv titlatorizer
// @namespace   Titlatorizer
// @description Replaces the arxiv title with the ... title.
// @include     http://arxiv.org/*
// @include     https://arxiv.org/*
// @version     0.0
// @grant       GM_xmlhttpRequest
// ==/UserScript==
//
// By Jasper den Ouden, based on
// https://github.com/musically-ut/arXiv-title-fixerarXiv-title-fixer
// by Utkarsh Upadhyay on MIT license
//
// MIT license is repeated below although relatively little is copied here.

function figure_title_from_xml(xml) {
    var feed = xml.childNodes[0];
    var paper_title = null;
    Array.prototype.slice.call(feed.children).forEach(function (child) {
        if (child.nodeName.toLowerCase() === 'entry') {
            var entry = child;
            Array.prototype.slice.call(entry.children).forEach(function (field) {
                if (field.nodeName.toLowerCase() === 'title') {
                    var title = field;
                    paper_title = title.childNodes[0].wholeText;
                }
            });
        }
    });
    return paper_title;
}

function figure_title() {
    var pathComponents = window.location.pathname.split('/');
    var pdfName = pathComponents[pathComponents.length - 1];
    var paperId = /([^v]*)(v[0-9]*)?\.pdf/.exec(pdfName)[1];
    if(paperId) {
        GM_xmlhttpRequest({
            method:'GET',
            url:"http://export.arxiv.org/api/query?id_list=" + paperId,
            onload:function (response) {
                if (response.status === 200) {
                    var responseXML =
                        (new DOMParser()).parseFromString(response.responseText, "text/xml");
                    var title = figure_title_from_xml(responseXML);
                    if(title){ document.title = title + " (" + paperId + ")"; }
                };
            }
        });
    }
}

figure_title();

// The MIT License (MIT)
// 
// Copyright (c) 2016 Utkarsh Upadhyay
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

It changes the title at first... But once the file is fully loaded, Chrome overrides it. Quite frustrating :/
I can't get it to wait till "page load" first.