FBTF: Clean up task.h in x11_util.h and header usage in some delegates.

FBTF: Clean up some headers in tab_contents_delegate.h.

BUG=none
TEST=none

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=55635

[Elliot Glaysher, 2010-08-10 20:50:14]

Removing headers from tab_contents_delegate.h has *much* more far reaching
influences than it should have. :(

[Lei Zhang, 2010-08-10 20:56:08]

LGTM assuming you fix the Windows build.

Ya, that rabbit hole went pretty deep.

[Lei Zhang, 2010-08-10 21:33:50]

Also, the description of this CL is incorrect.

[Elliot Glaysher, 2010-08-10 21:40:42]

I see what has happened. Somehow that chunk made its way into what I committed
as r55577. Thankfully, this didn't break the tree.

Obviously, I need to stop having six CLs open at a time, working on them all
concurrently.