... I have been experiencing the exact same problem, running my Mac Mini 2009, 256GB SSD, 8GB of RAM, Yosemite.
www.amazon.com, front page that big banner, it happened to me three times already. As soon as I get on that page, the banner (picture or some Ad) scrambles into these weird looking tiles (and only the banner is scrambled every time), looks like what your monitor would give you if your VGA/DVI cable was loose. Then the whole machine would freeze, it would then after a few second flash the whole screen then I would be able to move the mouse, it would then flash again and the mouse would be dead (whole machine freeze) and repeat. This happened to me a total of three times, the first time I had to do a hard restart, the second time I was able to struggle to get to activity monitor and kill safari, and the third time I had to do a hard restart again. I have not visited Amazon since.
...
But I guess I'm not the only one that's experiencing this particular problem. I have not update or change any hardware/software configuration before all this happened. As I'm typing this I suspect this could be the work of ABP? That would be the biggest factor to have on the browser when access any website.
Ps. I have other browser installed, but I don't use them. I only run Safari.