third_party/protobuf: Update to HEAD (83d681ee2c)

third_party/protobuf/src/google/protobuf/util/time_util.h

Index: third_party/protobuf/src/google/protobuf/util/time_util.h
diff --git a/third_party/protobuf/src/google/protobuf/util/time_util.h b/third_party/protobuf/src/google/protobuf/util/time_util.h
index 1bac089707985d7cc6350a6aaf7707afc64f1f12..432c9f0ae86647017f3be596a005c8282802fbca 100644
--- a/third_party/protobuf/src/google/protobuf/util/time_util.h
+++ b/third_party/protobuf/src/google/protobuf/util/time_util.h
@@ -28,6 +28,8 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+// Defines utilities for the Timestamp and Duration well known types.
+
 #ifndef GOOGLE_PROTOBUF_UTIL_TIME_UTIL_H__
 #define GOOGLE_PROTOBUF_UTIL_TIME_UTIL_H__
 
@@ -47,6 +49,7 @@ namespace google {
 namespace protobuf {
 namespace util {
 
+// Utility functions for Timestamp and Duration.
 class LIBPROTOBUF_EXPORT TimeUtil {
   typedef google::protobuf::Timestamp Timestamp;
   typedef google::protobuf::Duration Duration;