Get rid of the StyleResolver throwaway timer (try 2)

This the same as crrev.com/139153013.

BUG=335964,335247

Review URL: https://codereview.chromium.org/142023004

git-svn-id: svn://svn.chromium.org/blink/trunk@166333 bbb929c8-8fbe-4397-9dbb-9b2b20218538