angular/protractor — pull request #942 by ashaffer (2014-06-17 22:49:53+00:00)
Title: Add configurable delay between concurrent instances

When running a large number of instances simultaneously, launching many instances of chrome (maybe other browsers too, but I only tested with chrome) at exactly the same moment causes webdriver to fail with the error "cannot get automation extension from unknown error: failed to close UI debuggers".

Staggering their launch by 1 second or so seems to resolve this completely.