Upgrade TargetedStyleRecalc to status=stable.
Upgrade TargetedStyleRecalc to status=stable.

The feature has been at status=experimental for over a month, and all known bugs have been fixed.

BUG=335247

Review URL: https://codereview.chromium.org/208153007

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@169765 bbb929c8-8fbe-4397-9dbb-9b2b20218538

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