I am on Mountain Lion (OS 10.8.5), and I am using Chrome 32.0.1700.77. I notice that Chrome (the Google Chrome Helper to be precise) has developed the annoying habit of using ~ 10% of each CPU core (something it did not used to do), and the font rendering is increasingly erratic (i.e. Wikipedia or other pages change fonts as I scroll through a page). These problems can be either on my computer or a seriously buggy release of Chrome (which did not have these problems for me). If the former I'd like to have your opinion about a possible fix, if the latter I hope a new release of Chrome will come out soon...
According to this thread one of the possible culprits is the Chrome Extension AdBlock (which is pretty nice to have). A second possible culprit is some of the catalog indexing done by Quicksilver -- when I disabled the indexing of running processes and restarted Chrome I noticed a solid improvement in terms of lower CPU usage. The CPU usage is still, annoyingly, going up, albeit slowly, and I think this is due to Adblock (or maybe another extension, but I only have about 5). Because I like to avoid ads I will keep the Adblock extension running and restart Chrome from time to time until the issue is resolved.
Basically Chrome's CPU usage might be due to other apps interacting with it (Quicksilver in my case), and also due to Chrome Extensions, so it is worthwhile exploring these two avenues to try and improve Chrome's resources usage.
I have not found a cause or a cure for the erratic font behaviour.
Addendum 27/1/2014: another big improvement seems to be had by (1) installing the official Adobe's Flash Plugin and (2) deactivating Chrome's own Flash plugin so that it uses the Adobe's version.
Addendum 29/1/2014: yesterday Chrome autoupdated to 32.0.1700.102, and the issues of CPU usage seem resolved, i.e. there was little I could do on my end. To be honest I do not have the time to chase which plugin might minimise CPU use and whatnot, I hope Google will avoid releasing updates that have CPU usage bugs.
Addendum 3/2/2014: despite all the above Chrome's CPU usage would still creep up, slowly but inexorably. I reset to factory defaults, reset the fonts to the 'defaults' and thus far the CPU use seems to be under control.