Last month Google released a 64-bit version of the Chrome browser for OS X on its developer channel. However, this version of the app has not yet been made available to the general public. Google announced today in a blog post (via iMore) that the browser would be updated in version 39 not only to add 64-bit support, but to remove 32-bit support.
That means that any 32-bit plugins built on the Netscape Plugin API will no longer function until they are updated for 64-bit systems. This update will be released in November, though an exact release date hasn’t been given yet. Because Chrome uses a silent auto-update mechanism, users won’t have to do anything special to get the update.