Pull new version of protobuf sources.

third_party/protobuf/src/google/protobuf/arenastring.cc

Index: third_party/protobuf/src/google/protobuf/arenastring.cc
diff --git a/third_party/protobuf/src/google/protobuf/generated_message_util.cc b/third_party/protobuf/src/google/protobuf/arenastring.cc
similarity index 72%
copy from third_party/protobuf/src/google/protobuf/generated_message_util.cc
copy to third_party/protobuf/src/google/protobuf/arenastring.cc
index 92882d79ce7ae63cbf1964fc20474a0db6115609..cce61d74de241401917ef30c8a5a707fed10e177 100644
--- a/third_party/protobuf/src/google/protobuf/generated_message_util.cc
+++ b/third_party/protobuf/src/google/protobuf/arenastring.cc
@@ -1,6 +1,6 @@
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
-// http://code.google.com/p/protobuf/
+// https://developers.google.com/protocol-buffers/
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
@@ -28,35 +28,24 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Author: kenton@google.com (Kenton Varda)
-//  Based on original Protocol Buffers design by
-//  Sanjay Ghemawat, Jeff Dean, and others.
+// The ArenaString implementation is not included in the open-source release. Do
+// not include this file in the distribution.
 
-#include <google/protobuf/generated_message_util.h>
-
-#include <limits>
+#include <google/protobuf/arenastring.h>
 
 namespace google {
 namespace protobuf {
 namespace internal {
 
-double Infinity() {
-  return std::numeric_limits<double>::infinity();
-}
-double NaN() {
-  return std::numeric_limits<double>::quiet_NaN();
-}
-
-const ::std::string* empty_string_;
-ProtobufOnceType empty_string_once_init_;
-
-void InitEmptyString() {
-  empty_string_ = new std::string();
-}
 
-const ::std::string& GetEmptyString() {
-  GoogleOnceInit(&empty_string_once_init_, &InitEmptyString);
-  return *empty_string_;
+void ArenaStringPtr::AssignWithDefault(const ::std::string* default_value,
+                                       ArenaStringPtr value) {
+  const ::std::string* me = *UnsafeRawStringPointer();
+  const ::std::string* other = *value.UnsafeRawStringPointer();
+  // If the pointers are the same then do nothing.
+  if (me != other) {
+    SetNoArena(default_value, value.GetNoArena(default_value));
+  }
 }
 
 }  // namespace internal