The developer tools extension pages get access to the chrome.experimental.devtools.* APIs which are described further in our docs. Be sure to check out the sample extensions, which include extensions for jQuery and FirePHP users and a simple audit extension that finds broken links.
For a richer example, you can also check out Page Speed for Chromium, which uses the extensions API to provide Page Speed suggestions right in the Chrome Devtools UI.
We’re looking forward to seeing your feedback on the APIs and, of course, cool extensions coming to life!
In addition to the Developer Day, we will also have a booth on the Expo floor on Oct. 11th-12th where we’ll have representatives from the Chrome Web Store, Native Client, WebGL, App Engine, Google+, In-App Payments, Google TV, and AdSense/AdMob demoing technologies and platforms for game developers. Come by booth 503 to try out Google products and ask questions, or hang out in our Google TV lounge.
Not able to attend GDC? Check out Google Game Developer Central to get an overview of Google products and services that are particularly relevant to game developers.