folder is currently 390 megabytes and contains 88 files. In addition, Chrome stores files in
C:\Users\[windowsuserid]\AppData\Local\Google\Chrome\User Data
Many of the files in this second location are the browser cache, but, even ignoring the cache, Chrome has 3,768 files here consuming 239 megabytes.
Rather than do a full refresh for a small change, Google's second update system does small updates for small changes. The parts of Chrome that can be individually updated are called components and the Flash Player, embedded in Chrome, is one of these components.
Google mentions this in an article targeted at IT administrators called Manage Chrome updates on Windows. It makes a good first impression. The article says that the "Chrome Component Updater allows the Chrome engineering team to release small updates to parts of Chrome on a very rapid schedule." Compared to the full browser update, the article notes that the Component Updater uses a small amount of bandwidth and only runs when the browser itself is running.
The downside, for me at least, has been that there was no interface to the Chrome Component Updater.
The tip that I received (thanks Michael) was that there is, in fact, an interface to it, and, that the Component Updater can be used to update Flash.