Update //third_party/protobuf to version 3.

third_party/protobuf/src/google/protobuf/compiler/csharp/csharp_enum.h

 // 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
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
 // distribution.
 //     * Neither the name of Google Inc. nor the names of its
 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (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_COMPILER_CSHARP_ENUM_H__
+#define GOOGLE_PROTOBUF_COMPILER_CSHARP_ENUM_H__
 
 #include <string>
 
-#include <google/protobuf/stubs/common.h>
+#include <google/protobuf/compiler/code_generator.h>
+#include <google/protobuf/compiler/csharp/csharp_source_generator_base.h>
+
 namespace google {
 namespace protobuf {
 namespace compiler {
-namespace cpp {
+namespace csharp {
 
-// Generator options:
-struct Options {
-  Options() : safe_boundary_check(false) {
-  }
-  string dllexport_decl;
-  bool safe_boundary_check;
+class EnumGenerator : public SourceGeneratorBase {
+ public:
+  EnumGenerator(const EnumDescriptor* descriptor);
+  ~EnumGenerator();
+
+  void Generate(io::Printer* printer);
+
+ private:
+  const EnumDescriptor* descriptor_;
+
+  GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(EnumGenerator);
 };
 
-}  // namespace cpp
+}  // namespace csharp
 }  // namespace compiler
 }  // namespace protobuf
+}  // namespace google
 
+#endif  // GOOGLE_PROTOBUF_COMPILER_CSHARP_ENUM_H__
 
-}  // namespace google
-#endif  // GOOGLE_PROTOBUF_COMPILER_CPP_OPTIONS_H__