Chrome Developer Tools is capable of running a custom user stylesheet.
Place Custom.css in the following folder:
~/Library/Application Support/Google/Chrome/Default/User StyleSheets/
C:\Documents and Settings\<username>\Local Settings\Application Data\Google\Chrome\User Data\Default\User Stylesheets\
C:\Users\<username>\AppData\Local\Google\Chrome\User Data\Default\User StyleSheets\
~/.config/google-chrome/Default/User StyleSheets/
James Tomasino, github@jamestomasino.com, http://jamestomasino.com,