The updates are really small. As they've detailed in a number of blog posts, the patch format is a custom binary diff that understands the format of ELF/EXE/etc. file formats to get the smallest diffs possible.
Also, on Linux systems Chrome does not automatically update. When you download the deb/rpm from Google it sets up a package repository (e.g. by adding a file like /etc/yum.repos.d/google-chrome.repo) and you get updates via the usual package update mechanism on your system. I have no idea if this will ever happen, but it seems like if there was a better integrated update system for OS X and Windows then Chrome on those systems could have an option to work in a similar way.
It's not really the size but the principle of it. Google is installing something on my PC without asking me about it. Ev6en if in this case the result is good, it's not the kind of thing a program should do.
I know that when one installs Chrome, they are implicitly accepting that it will update itself, but it still is a very unique behaviour that wouldn't be accepeted in most programs.
When gmail rolls out an update, do you want to pre-approve it also? The only thing google does with chrome is bring the web model of automatic updates to a desktop app.
If you think about it, the only reason we want the control is because we don't trust software companies not to mess up our system. The crazy thing is wanting manual updates, because it implies gross incompetence from the software industry.
Well. Personally I see a whole lot of difference between web applications and code running on my machine.
In the case of gmail, I rely on their code only for checking/sending mail. And they have access to just my mail data. When something runs on my machine, I need to be a lot more careful about what data that code has access to and what privileges it has.
Since email is used to recover lost passwords, just checking/sending mail is equivalent to "the keys to every website I have an account on". By trusting Google to keep your email safe, you're trusting them to keep your entire online presence safe. In that light, letting someone run code on your computer seems relatively tame.
Also, on Linux systems Chrome does not automatically update. When you download the deb/rpm from Google it sets up a package repository (e.g. by adding a file like /etc/yum.repos.d/google-chrome.repo) and you get updates via the usual package update mechanism on your system. I have no idea if this will ever happen, but it seems like if there was a better integrated update system for OS X and Windows then Chrome on those systems could have an option to work in a similar way.