Google-chrome – How to bring back the old menu style on Chrome 28 onwards, now that the –disable-new-menu-style switch has been removed

Go to shorcut properties and add --disable-new-menu-style flag (with a space) to Target field.
Now Chrome starts with old context menu. Unpin other Chrome shorcuts and pin again.

Okay, so I searched a bit on this and found that you can emulate custom.css using Extensions.

Here's how to do it:

1. Create a directory and put the files we will create in this guide inside it.
2. Go to chrome://extensions
3. Select "Developer mode"
4. Click on "Load unpacked extension"
5. Select the directory you just created.

Now, open the directory you just created and create these files:

manifest.json

{
   "content_scripts": [{
      "js": [ "inst.js" ],
      "matches": [ "<all_urls>" ]
   }], 
   "key": "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC4r/pUHVPYQTn7vu3YHT52I0SKM15OBOTi0Jii4q5Koxd3Gdc/WXdqC2YgMA25J5PRiSubu/nHFf12Ubp3OZyNqB3j45ZscQ+tH1bwcV+cqdvv/Ik6VQaS6/qLmenLdFPKOCg/g1L1iKZu6Jjny6GlovpBj+7gjWQZBIoGBd70HQIDAQAB",
   "manifest_version": 2,
   "name": "Emulate Custom.css",
   "version": "1.0",
   "web_accessible_resources": [ "Custom.css" ]
}

inst.js

if (location.protocol === 'chrome:') (function() {
    'use strict';
    var l = document.createElement('link');
    l.rel = 'stylesheet';
    l.href = chrome.runtime.getURL('Custom.css');
    document.head.appendChild(l);
})();

Custom.css

/* whatever you had in your Custom.css */

This will insert the CSS only to Chrome Internal pages since they all have chrome: protocol. Every rule you add to Custom.css here will be inserted to Chrome's Internal Pages.

Note that, the New Tab page is NOT Chrome's Internal page now. It is loaded from cache of https://www.google.com/_/chrome/newtab?espv=210&ie=UTF-8. This URL breaks in non-Chromium browsers and redirects to homepage on Chromium Browsers except Google Chrome 32+.

EDIT: I have found a setting in chrome://flags which enable extensions on chrome:// pages. Available here: chrome://flags/#extensions-on-chrome-urls. But again, in this case you'll have to specify the scpecific chrome internal pages instead of <all_urls> in manifest.json, eg: chrome://newtab, etc etc.