GitLab

UMA metrics indicate we have great validity. Enable the hit test cache
in release by default. Keep the validity checks around in ASSERTs
are enabled.

BUG=398920

Review URL: https://codereview.chromium.org/1294913004

git-svn-id: svn://svn.chromium.org/blink/trunk@200852 bbb929c8-8fbe-4397-9dbb-9b2b20218538