This is weird. A few months ago I had the plugin running just fine in Chrome. Now it's not showing up (OSX 10.9.5, Chrome Version 40.0.2214.111 (64-bit)).
When I go to http://www.google.com/intl/en/earth/explore/products/plugin.html I see the [Download the Google Earth Plugin] button. When I click, download and open dmg file I get the "Google Earth Web Plug-in" and double click that. I see it run the process and say 'Copying "Google Earth Web Plug-in.plugin" to "Internet Plug-Ins"'. But when I look in "/Library/Internet Plug-Ins", there is no Google anything. And when I restart Chrome and go back to http://www.google.com/intl/en/earth/explore/products/plugin.html I still see the [Download the Google Earth Plugin].
Weirdly enough however the plugin is working in Safari and Firefox.