Do not include RefCounted header files to OwnPtrCommon.h

Do not include RefCounted header files to OwnPtrCommon.h - forward declaration should be used instead.

Review URL: https://codereview.chromium.org/39903002

git-svn-id: svn://svn.chromium.org/blink/trunk@160461 bbb929c8-8fbe-4397-9dbb-9b2b20218538