ANGLETest: set viewport after resizing to help apitrace Otherwise apitrace doesn't know the dimension of the framebuffer and cannot display it. BUG=angleproject:892 Change-Id: Ib8ad846ca80e4783ab77c96430bb5220df1a39ab Reviewed-on: https://chromium-review.googlesource.com/286881 Reviewed-by: Jamie Madill <jmadill@chromium.org> Tested-by: Corentin Wallez <cwallez@chromium.org>