Move Document::m_hasPendingStyleRecalc into the DocumentLifecycle

This CL removes the m_hasPendingStyleRecalc bool from Document and instead
moves the state into the DocumentLifecycle state machine. As requested in the
previous review, I've moved the Clean state after all the states that clean out
dirty bits.

BUG=282720
R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/140183003

git-svn-id: svn://svn.chromium.org/blink/trunk@166251 bbb929c8-8fbe-4397-9dbb-9b2b20218538