Disable concurrency test added in r50903
Disable concurrency test added in r50903

It fails on ChromeOS.

TBR=wtc
BUG=47587
TEST=KeygenHandlerTest.ConcurrencyTest

Review URL: http://codereview.chromium.org/2880003

git-svn-id: http://src.chromium.org/svn/trunk/src@50915 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: fe1f32b83e0f616f3a81a8972c27f1732e1a24f3
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser