content: Delete webkit_support_glue.cc file.

This file may have been necessary to implement some methods that were
declared in webkit land. But as far as we can see this is not case
anymore and thus we can remove it now.

BUG=None
TEST=content_unittests
R=jam@chromium.org

Review URL: https://codereview.chromium.org/183123007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@254533 0039d316-1c4b-4281-b951-d872f2087c98
Updating trunk VERSION from 1869.0 to 1870.0

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@254534 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 254534