Update //third_party/protobuf to version 3.

third_party/protobuf/csharp/src/Google.Protobuf.Test/SampleEnum.cs

Index: third_party/protobuf/csharp/src/Google.Protobuf.Test/SampleEnum.cs
diff --git a/third_party/protobuf/src/google/protobuf/unittest_import_public.proto b/third_party/protobuf/csharp/src/Google.Protobuf.Test/SampleEnum.cs
similarity index 80%
copy from third_party/protobuf/src/google/protobuf/unittest_import_public.proto
copy to third_party/protobuf/csharp/src/Google.Protobuf.Test/SampleEnum.cs
index ea5d1b13fea77a432cecc0980664c020159d108a..77447afa127340046298081d9bfca4dd51c14f6c 100644
--- a/third_party/protobuf/src/google/protobuf/unittest_import_public.proto
+++ b/third_party/protobuf/csharp/src/Google.Protobuf.Test/SampleEnum.cs
@@ -1,6 +1,7 @@
+#region Copyright notice and license
 // Protocol Buffers - Google's data interchange format
-// Copyright 2008 Google Inc.  All rights reserved.
-// http://code.google.com/p/protobuf/
+// Copyright 2015 Google Inc.  All rights reserved.
+// 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
@@ -27,14 +28,15 @@
 // 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: liujisi@google.com (Pherl Liu)
-
-
-package protobuf_unittest_import;
-
-option java_package = "com.google.protobuf.test";
-
-message PublicImportMessage {
-  optional int32 e = 1;
+#endregion
+    
+namespace Google.Protobuf
+{
+    // Just a sample enum with positive and negative values to be used in tests.
+    internal enum SampleEnum
+    {
+        NegativeValue = -2,
+        None = 0,
+        PositiveValue = 3
+    }
 }