Fix error logging in ValidateBlitFramebufferANGLE Bundle an error message about whole buffer copies inside gl::Error instead of delivering it to the Platform. BUG=angleproject:1660 Change-Id: I13205b74529fbe40af05e7c1896c6315486e90e0 Reviewed-on: https://chromium-review.googlesource.com/437628 Commit-Queue: Yuly Novikov <ynovikov@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>