OSNews posted a story that Google will drop support for OS X 10.5 in Chrome 21

Google Chrome on Mac OS X 10.5 (Leopard) will stop receiving any updates following Chrome 21. This includes new features, security fixes and stability updates. [...] If you already have Chrome installed, you can still use Chrome, but it will no longer be auto-updated. In addition, you'll be unable to install Chrome on any Mac still running 10.5 (which is an OS X version also no longer being updated by Apple). While we understand this is an inconvenience, we are making this change to ensure we can continue to deliver a safe, secure, and stable Chrome for the most Mac users possible." I'm okay with this - Snow Leopard was released in August 2009, so it's been three years since the last machines with Leopard shipped.

  Chrome 21 to drop support for Mac OS X 10.5