Make RecursionData a stack-allocated variable in StyleInvalidator, since it is only
used during a single invalidation.

These makes makes its intended object data lifetime clearer and avoids possible bugs.

BUG=379908

Review URL: https://codereview.chromium.org/416243003

git-svn-id: svn://svn.chromium.org/blink/trunk@179050 bbb929c8-8fbe-4397-9dbb-9b2b20218538