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’re not sure what OS version you’re on, go to the Apple icon on the top left corner and click About This Mac to find out. 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 In addition, you’ll be unable to install Chrome on any Mac still running 10.5 (which is an OS X version also no longer being updated by Apple).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.
Upgrading your Mac to 10.6 (Snow Leopard) or 10.7 (Lion) will enable us to begin automatically updating Chrome.