WebUpd8 reader conorsulli just sent us a tip about an Elementary scrollbars extension he's made for Google Chrome / Chromium. Even though the scrollbars are especially designed for Elementary and other GTK themes based on Elementary, the extension will of course work with any GTK theme.
To use, extract the downloaded .zip, then drag and drop the .crx file onto the Chrome window.
Download Elementary scrollbars 4 Chrome @ DeviantArt
[Screenshot thanks to conorsulli]