What is x3d? Help needed deciphering console crash log
Try clearing all your cache files for your browsers. I was having the same issue with the same crash log for the last few days. I took it to the Apple Store for that and another unrelated issue with my display. They cleared out the cache folder for Chrome, and the issue quit just like that. No more freezing browser, no more crash logs. I was a little embarrassed I hadn't tried that, when I'd tried just about everything else I could think of. There seemed to be a chrome and/or x3d daemon that was hanging. Hopefully that will clear up your problem as well.