Google Chrome Helper for "GPU Process" constantly shown as non responsive in OS X 10.9
I've been experiencing the same issue for about a month, except it predates Mavericks (10.9) when I was still using Mountain Lion (10.8.4 and 10.8.5 specifically).

I've found the only way I can remedy the issue is to force quit the unresponsive Google Chrome Helper and all other associated processes (all "Google Chrome ..." named items) except for Google Chrome itself (the one with the icon). That will crash most, if not all, browser plugins, but it will make Chrome useable for a decent amount of time if you keep down on your number of open tabs.

It's not fantastic by any means, but my other remedy is going back to using Firefox for the time being and keeping my fingers crossed Google is working on a fix for this issue.

MacBook Pro 6,2 (15-inch Mid-2010)
2.53GHz Intel i5
4GB RAM
128GB SanDisk Ultra Plus SSD/500GB Toshiba HDD
OS X 10.9 "Mavericks"