Fix GN errors in WebKit build files.

BUG=

Review URL: https://codereview.chromium.org/31373005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230156 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230156
Add BUILD.gn files for weborigin/weborigin_unittests

Review URL: https://codereview.chromium.org/27780002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230157 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230157