Remove PassOwnPtr non-member comparison operators

Before the change there was a weird situation with PassOwnPtr comparison operators: class member comparison  operators were defined and their usage was forbidden in compile time (as we should never have two OwnPtrs for the same underlying object), but at the same time non-member comparison operators were defined and their usage was not forbidden.
This CL removes PassOwnPtr non-member comparison operators.

Review URL: https://codereview.chromium.org/39593005

git-svn-id: svn://svn.chromium.org/blink/trunk@160524 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Refactoring: Turn FontFaceSet into a Document supplement.

Document and FontFaceset doesn't interact at all.
Such a class is better off to be a supplement to reduce
the Document class complexity.

R=tkent
BUG=none
TEST=none

Review URL: https://codereview.chromium.org/43003002

git-svn-id: svn://svn.chromium.org/blink/trunk@160525 bbb929c8-8fbe-4397-9dbb-9b2b20218538