Allows you to define rules that automatically add or change html attributes or css styles for elements you specify in a website.
1. Add the addon on the Chrome Web Store.
2. Left click on the extension's icon in the top right, to the right of the URL bar. Then click on the addon's icon, and select the Define rules button from the popup.
3. I recommend taking the rules from the recommendedRules.json (https://github.com/jtank4/Attribute-and-Style-Editor/blob/Chrome/rules/recommendedRules.json) file in this repository, pasting them into the rules text area, and clicking the Save button below the rules text area. These recommended rules add controls (time scrub bar, volume bar) to videos on instagram.com and audios and videos on tumblr.com. They are also a good starting point for you to create your own rules.
For more details on the use of this addon, check out the repository and readme file at https://github.com/jtank4/Attribute-and-Style-Editor/tree/Chrome