I think Google updates them in the background (no notification), and doe snot ask for a browser restart when you eventually do restart it, it is updated to the new version. I think, because I've seen version numbers go up without doing anything.
I just use plain Chrome at the minute. The built in "inspect element" tools replaces firebug for me so I've totally ditched Firefox currently... it's been so buggy of late it's drove me insane.
I design websites and sell my work on online marketplaces where screenshots are a must and tools like this speed up taking screenshots no need to open it up in photoshop.
Brilliant thanks for the will be using both but for now Awesome screenshot seems to be a bit better considering Lightshots editor or upload feature doesn't seem to be working