Pull new version of protobuf sources.

third_party/protobuf/src/google/protobuf/proto_cast.h

Index: third_party/protobuf/src/google/protobuf/proto_cast.h
diff --git a/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_options.h b/third_party/protobuf/src/google/protobuf/proto_cast.h
similarity index 67%
copy from third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_options.h
copy to third_party/protobuf/src/google/protobuf/proto_cast.h
index 787706629bd10fc72eb7811d9498f19dd0524d11..e25c219ffece24b132fa9f9f6280186efba50cf2 100644
--- a/third_party/protobuf/src/google/protobuf/compiler/cpp/cpp_options.h
+++ b/third_party/protobuf/src/google/protobuf/proto_cast.h
@@ -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
@@ -28,31 +28,31 @@
 // (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: rennie@google.com (Jeffrey Rennie)
-
-#ifndef GOOGLE_PROTOBUF_COMPILER_CPP_OPTIONS_H__
-#define GOOGLE_PROTOBUF_COMPILER_CPP_OPTIONS_H__
+#ifndef GOOGLE_PROTOBUF_UTIL_PROTO_CAST_H__
+#define GOOGLE_PROTOBUF_UTIL_PROTO_CAST_H__
 
 #include <string>
 
 #include <google/protobuf/stubs/common.h>
-namespace google {
-namespace protobuf {
-namespace compiler {
-namespace cpp {
-
-// Generator options:
-struct Options {
-  Options() : safe_boundary_check(false) {
-  }
-  string dllexport_decl;
-  bool safe_boundary_check;
-};
 
-}  // namespace cpp
-}  // namespace compiler
-}  // namespace protobuf
+// proto_cast<> is used to simulate over-the-wire conversion of one
+// proto message into another.  This is primarily useful for unit tests
+// which validate the version-compatibility semantics of protobufs.
+// Usage is similar to C++-style typecasts:
+//
+// OldMessage old_message = /*...*/;
+// NewMessage new_message = proto_cast<NewMessage>(old_message);
+namespace google {
+template<typename NewProto,
+         typename OldProto>
+NewProto proto_cast(const OldProto& old_proto) {
+  string wire_format;
+  GOOGLE_CHECK(old_proto.SerializeToString(&wire_format));
 
+  NewProto new_proto;
+  GOOGLE_CHECK(new_proto.ParseFromString(wire_format));
+  return new_proto;
+}
 
 }  // namespace google
-#endif  // GOOGLE_PROTOBUF_COMPILER_CPP_OPTIONS_H__
+#endif  // GOOGLE_PROTOBUF_UTIL_PROTO_CAST_H__