Update //third_party/protobuf to version 3.

third_party/protobuf/csharp/src/Google.Protobuf/Compatibility/TypeExtensions.cs

Index: third_party/protobuf/csharp/src/Google.Protobuf/Compatibility/TypeExtensions.cs
diff --git a/third_party/protobuf/csharp/src/Google.Protobuf/Compatibility/TypeExtensions.cs b/third_party/protobuf/csharp/src/Google.Protobuf/Compatibility/TypeExtensions.cs
new file mode 100644
index 0000000000000000000000000000000000000000..762a29eb0a3018d8f5d8eb37f83a50326c34d3bf
--- /dev/null
+++ b/third_party/protobuf/csharp/src/Google.Protobuf/Compatibility/TypeExtensions.cs
@@ -0,0 +1,113 @@
+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// 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
+// 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.
+#endregion
+
+using System;
+using System.Reflection;
+
+namespace Google.Protobuf.Compatibility
+{
+    /// <summary>
+    /// Provides extension methods on Type that just proxy to TypeInfo.
+    /// These are used to support the new type system from .NET 4.5, without
+    /// having calls to GetTypeInfo all over the place. While the methods here are meant to be
+    /// broadly compatible with the desktop framework, there are some subtle differences in behaviour - but
+    /// they're not expected to affect our use cases. While the class is internal, that should be fine: we can
+    /// evaluate each new use appropriately.
+    /// </summary>
+    internal static class TypeExtensions
+    {
+        /// <summary>
+        /// Returns true if the target type is a value type, including a nullable value type or an enum, or false
+        /// if it's a reference type (class, delegate, interface - including System.ValueType and System.Enum).
+        /// </summary>
+        internal static bool IsValueType(this Type target)
+        {
+            return target.GetTypeInfo().IsValueType;
+        }
+
+        /// <summary>
+        /// See https://msdn.microsoft.com/en-us/library/system.type.isassignablefrom
+        /// </summary>
+        internal static bool IsAssignableFrom(this Type target, Type c)
+        {
+            return target.GetTypeInfo().IsAssignableFrom(c.GetTypeInfo());
+        }
+
+        /// <summary>
+        /// Returns a representation of the public property associated with the given name in the given type,
+        /// including inherited properties or null if there is no such public property.
+        /// Here, "public property" means a property where either the getter, or the setter, or both, is public.
+        /// </summary>
+        internal static PropertyInfo GetProperty(this Type target, string name)
+        {
+            // GetDeclaredProperty only returns properties declared in the given type, so we need to recurse.
+            while (target != null)
+            {
+                var typeInfo = target.GetTypeInfo();
+                var ret = typeInfo.GetDeclaredProperty(name);
+                if (ret != null && ((ret.CanRead && ret.GetMethod.IsPublic) || (ret.CanWrite && ret.SetMethod.IsPublic)))
+                {
+                    return ret;
+                }
+                target = typeInfo.BaseType;
+            }
+            return null;
+        }
+
+        /// <summary>
+        /// Returns a representation of the public method associated with the given name in the given type,
+        /// including inherited methods.
+        /// </summary>
+        /// <remarks>
+        /// This has a few differences compared with Type.GetMethod in the desktop framework. It will throw
+        /// if there is an ambiguous match even between a private method and a public one, but it *won't* throw
+        /// if there are two overloads at different levels in the type hierarchy (e.g. class Base declares public void Foo(int) and
+        /// class Child : Base declares public void Foo(long)).
+        /// </remarks>
+        /// <exception cref="AmbiguousMatchException">One type in the hierarchy declared more than one method with the same name</exception>
+        internal static MethodInfo GetMethod(this Type target, string name)
+        {
+            // GetDeclaredMethod only returns methods declared in the given type, so we need to recurse.
+            while (target != null)
+            {
+                var typeInfo = target.GetTypeInfo();
+                var ret = typeInfo.GetDeclaredMethod(name);
+                if (ret != null && ret.IsPublic)
+                {
+                    return ret;
+                }
+                target = typeInfo.BaseType;
+            }
+            return null;
+        }
+    }
+}