Mark inspector-protocol/stylesheet-tracking-restart.html as flaky

BUG=334242
TBR=dstockwell,apavlov

Review URL: https://codereview.chromium.org/133153004

git-svn-id: svn://svn.chromium.org/blink/trunk@165066 bbb929c8-8fbe-4397-9dbb-9b2b20218538