Don't include the test main files in the source listings. Since chrome adds the ANGLE test source directly to it's own projects, the main function is defined twice. Remove the main file from the source listings and only add it for our test executables. BUG=angle:568 Change-Id: I30b481a23d5de80341d7f339583a43ad2f4391bb Reviewed-on: https://chromium-review.googlesource.com/195345 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Shannon Woods <shannonwoods@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>