perf test: Add PerfTestRunner.logFatalError(text)

Add PerfTestRunner.logFatalError(text) to stop a test if the test can not run.
For example, WebGL is not supported on some platforms, so a WebGL perf test on
the platform should stop.

BUG=242244

Review URL: https://codereview.chromium.org/198873004

git-svn-id: svn://svn.chromium.org/blink/trunk@169380 bbb929c8-8fbe-4397-9dbb-9b2b20218538