Remove duplicate includes for unit_test targets.

This fixes some of the multiple definition errors while building
unit_tests as a shared library.

BUG=
TEST=


Review URL: https://chromiumcodereview.appspot.com/10541176

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@142299 0039d316-1c4b-4281-b951-d872f2087c98
2 files changed