I have downloaded the patch releases 5.01p2, p3, but then I kept on getting errors both in Chrome as well Firefox on both of the patches and had to reverse back to 5.01p1 in order to make the WebGL back to work.
You should raise a bug report Unity IDE → Help → Report Bug
Ha, ha, WebGL builds do not work on p2,p3, and bug reports also do not seem to work on my computer at all. I have recenty sent a number of reports. Each time I was getting a message saying that the report has been sent and I will get a mail confirmation and then nothing more get happening no matter that I have a pro licence. And no trace of the report on the issue tracker.
There was a bug related to WebGL and stripping which sneaked into the latest patch releases. This is now fixed, so try if it works in 5.0.1p4, once that is out.