Safari under Yosemite Crashing my Macbook Pro

Browsing some site or other, it does not matter which...

In this case playing a video on Facebook.

A window pops up with "A graphics error has been detected" bla bla bla

Did not forward to Apple this time but did in the past.

Strange tick tick tick audio...

Then CRASH

Macbook Pro shuts down totally.

Did not have this problem with any earlier operating systems although never happy with Mavericks for many reasons.

Had this happen 3-4 times now.

No Safari extensions installed and turned off anyway.

Flash Player is the latest version.