Re-add performance information about cached CSSValues when cached stylesheet is restored.

BUG=337065
TEST=http/tests/css/performance-info-with-cached-sheet.html

Review URL: https://codereview.chromium.org/227433019

git-svn-id: svn://svn.chromium.org/blink/trunk@172750 bbb929c8-8fbe-4397-9dbb-9b2b20218538