GL: Only log all GL driver errors on debug builds Anything that invokes localtime_r() from the GPU process can be a slow operation on Linux. ANGLE's ClearErrors() function sometimes spams many errors, sometimes repeating every frame. These errors aren't necessary to print in release builds, and only logging these in debug builds will mitigate a lot of GPU process hangs. Bug: chromium:1077735 Change-Id: Ic1186732d477dee12caae0cb400e1d3504a0bd8b Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3546718 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jonah Ryan-Davis <jonahr@google.com>