Update third_party/protobuf to protobuf-v3.0.0-beta-3

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

 #region Copyright notice and license
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 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
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
@@ skipping 369 matching lines @@
                 Assert.AreEqual(125, cin.Position);
                 // Field 3: fixed numeric value: 501
                 tag = cin.ReadTag();
                 Assert.AreEqual(3, tag >> 3);
                 Assert.AreEqual(126, cin.Position);
                 Assert.AreEqual(501, cin.ReadSFixed32());
                 Assert.AreEqual(130, cin.Position);
                 Assert.IsTrue(cin.IsAtEnd);
             }
         }
+
+        [Test]
+        public void Dispose_DisposesUnderlyingStream()
+        {
+            var memoryStream = new MemoryStream();
+            Assert.IsTrue(memoryStream.CanWrite);
+            using (var cos = new CodedOutputStream(memoryStream))
+            {
+                cos.WriteRawByte(0);
+                Assert.AreEqual(0, memoryStream.Position); // Not flushed yet
+            }
+            Assert.AreEqual(1, memoryStream.ToArray().Length); // Flushed data from CodedOutputStream to MemoryStream
+            Assert.IsFalse(memoryStream.CanWrite); // Disposed
+        }
+
+        [Test]
+        public void Dispose_WithLeaveOpen()
+        {
+            var memoryStream = new MemoryStream();
+            Assert.IsTrue(memoryStream.CanWrite);
+            using (var cos = new CodedOutputStream(memoryStream, true))
+            {
+                cos.WriteRawByte(0);
+                Assert.AreEqual(0, memoryStream.Position); // Not flushed yet
+            }
+            Assert.AreEqual(1, memoryStream.Position); // Flushed data from CodedOutputStream to MemoryStream
+            Assert.IsTrue(memoryStream.CanWrite); // We left the stream open
+        }
     }
 }