As for the application ID, Google points to their manager Brian Rakowski, who at the Chromium project issues site states:

"There’s a little confusion here that I’d like to clear up. There are two IDs being discussed. They are stored and used separately.

First of all, there is an installation ID (iid) which is created at install time to de-dup install counts. This is necessary to accurately count the number of successful installations that have occurred. The iid is generated randomly (not based on any other information) and is deleted in the next update check after first run.

There is a second ID called the clientID which is used for the user metrics service. This is an opt-in service that lets users send usage statistics to Google so that we can learn how the product is being used for the sake of making improvements. It helps us answer questions like, “Are people using the back button?” and “How common is it that people click the back button repeatedly?” Users can always update their preference about sending usage statistics on the “Under the Hood” tab of options."