third_party/protobuf: Update to HEAD (83d681ee2c)

third_party/protobuf/src/google/protobuf/generated_message_util.cc

Index: third_party/protobuf/src/google/protobuf/generated_message_util.cc
diff --git a/third_party/protobuf/src/google/protobuf/generated_message_util.cc b/third_party/protobuf/src/google/protobuf/generated_message_util.cc
index 334051a013e4098afea6eed399a54caae30ac729..683a9d5c738c7c81ce9d2d03dc284844d773ed89 100644
--- a/third_party/protobuf/src/google/protobuf/generated_message_util.cc
+++ b/third_party/protobuf/src/google/protobuf/generated_message_util.cc
@@ -48,15 +48,13 @@ double NaN() {
   return std::numeric_limits<double>::quiet_NaN();
 }
 
-const ::std::string* empty_string_;
+ExplicitlyConstructed< ::std::string> fixed_address_empty_string;
 GOOGLE_PROTOBUF_DECLARE_ONCE(empty_string_once_init_);
 
-void DeleteEmptyString() {
-  delete empty_string_;
-}
+void DeleteEmptyString() { fixed_address_empty_string.Shutdown(); }
 
 void InitEmptyString() {
-  empty_string_ = new string;
+  fixed_address_empty_string.DefaultConstruct();
   OnShutdown(&DeleteEmptyString);
 }
 
@@ -79,6 +77,10 @@ int StringSpaceUsedExcludingSelf(const string& str) {
 
 
 
+void InitProtobufDefaults() {
+  GetEmptyString();
+}
+
 }  // namespace internal
 }  // namespace protobuf
 }  // namespace google