Wrong pending sheets test causing FOUC.

In r176050, moving the full view repaint from StyleEngine to Document, the
check changed from !hasPendingSheets() to haveStylesheetsLoaded(). The
difference is that m_ignorePendingStylesheets affected the result of the
check which causes a FOUC in named BUG.

BUG=384969

Review URL: https://codereview.chromium.org/339573005

git-svn-id: svn://svn.chromium.org/blink/trunk@176367 bbb929c8-8fbe-4397-9dbb-9b2b20218538