content: Remove webkit_unit_test_support.* component.

content: Remove webkit_unit_test_support.* component.

Blink was updated to not use it, and instead call the functions from
webkit_support.* because the former was just a wrapper that in turns was
just calling the functions from webkit_support.*

So since Blink is not using webkit_unit_test_support.* anymore and
nobody elses on Chromium uses it we can remove it now.

Blink change was landed in:
https://src.chromium.org/viewvc/blink?view=rev&revision=178440

BUG=None
TEST=webkit_unit_tests
R=jochen@chromium.org

Review URL: https://codereview.chromium.org/403203002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@285234 0039d316-1c4b-4281-b951-d872f2087c98