third_party/protobuf: Update to HEAD (83d681ee2c)

third_party/protobuf/csharp/src/Google.Protobuf.Test/WellKnownTypes/FieldMaskTest.cs

 #region Copyright notice and license
 // Protocol Buffers - Google's data interchange format
 // Copyright 2016 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 28 matching lines @@
     {
         [Test]
         [TestCase("foo__bar")]
         [TestCase("foo_3_ar")]
         [TestCase("fooBar")]
         public void ToString_Invalid(string input)
         {
             var mask = new FieldMask { Paths = { input } };
             var text = mask.ToString();
             // More specific test below
-            Assert.That(text, Is.StringContaining("@warning"));
-            Assert.That(text, Is.StringContaining(input));
+            Assert.That(text, Does.Contain("@warning"));
+            Assert.That(text, Does.Contain(input));
         }
 
         [Test]
         public void ToString_Invalid_Precise()
         {
             var mask = new FieldMask { Paths = { "x", "foo__bar", @"x\y" } };
             Assert.AreEqual(
                 "{ \"@warning\": \"Invalid FieldMask\", \"paths\": [ \"x\", \"foo__bar\", \"x\\\\y\" ] }",
                 mask.ToString());
         }
     }
 }