Added a gtest environment class to initialize the ANGLETest class window. Change-Id: I6fa59201364960cc8fe1cb44e2d09a14cf61dd8a Reviewed-on: https://chromium-review.googlesource.com/179352 Reviewed-by: Nicolas Capens <nicolascapens@chromium.org> Commit-Queue: Nicolas Capens <nicolascapens@chromium.org> Tested-by: Nicolas Capens <nicolascapens@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>