Remove uneeded page/ header includes

If it builds, it works.  Tested building on Linux.

TBR=abarth@chromium.org
BUG=305811

Review URL: https://codereview.chromium.org/115343004

git-svn-id: svn://svn.chromium.org/blink/trunk@163895 bbb929c8-8fbe-4397-9dbb-9b2b20218538