Make it possible to build DRT in a chromium checkout.

Make it possible to build DRT in a chromium checkout.

The problem was the circular gyp dependency between webkit.gyp
and WebKit.gyp:
webkit.gyp:pull_in_webkit_unit_tests -> WebKit.gyp -> webkit.gyp:webkit_support.

The fix is to move webkit_support into its own gyp file (like we do
in an webkit only checkout).  We can't use the same gyp file for in-
chromium and in-webkit because we need to change the include path for
features.gypi.  In gyp, variable expansion happens after includes
(otherwise you'd have to expand variables twice and they could change
values), so we can't use a single gyp file for this.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=47012

[tony, 2010-05-12 05:44:59]

This patch fixes the circular dependency, but it moves some library targets from
webkit into webkit/support.  I don't think that's a big deal.

[darin (slow to review), 2010-05-12 06:09:34]

LGTM

http://codereview.chromium.org/1995013/diff/11001/12012
File webkit/support/webkit_support.gyp (right):

http://codereview.chromium.org/1995013/diff/11001/12012#newcode6
webkit/support/webkit_support.gyp:6: # This file is the same as
webkit_support.gyp except it references
nit: webkit_support.gyp -> webkit_support_in_chromium.gyp

http://codereview.chromium.org/1995013/diff/11001/12013
File webkit/support/webkit_support_in_chromium.gyp (right):

http://codereview.chromium.org/1995013/diff/11001/12013#newcode9
webkit/support/webkit_support_in_chromium.gyp:9: #
webkit_support_in_chromium.gyp as well.
nit: webkit_support_in_chromium.gyp -> webkit_support.gyp