Don't append newline to empty InfoLog stream. Users were seeing different behavior when querying GL_INFO_LOG_LENGTH with ANGLE because ANGLE was always adding a newline to the InfoLog. Bug: chromium:1191293 Change-Id: I50f56326871cdd2f6614f5b1622257845721244c Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2795164 Commit-Queue: Jonah Ryan-Davis <jonahr@google.com> Reviewed-by: Kenneth Russell <kbr@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>