Revert https://codereview.chromium.org/1291903002 (protobuf roll).

third_party/protobuf/csharp/src/Google.Protobuf/Reflection/DescriptorUtil.cs

Index: third_party/protobuf/csharp/src/Google.Protobuf/Reflection/DescriptorUtil.cs
diff --git a/third_party/protobuf/csharp/src/Google.Protobuf/Reflection/DescriptorUtil.cs b/third_party/protobuf/csharp/src/Google.Protobuf/Reflection/DescriptorUtil.cs
deleted file mode 100644
index f5570fc40a24f9e91017280b4f6389607be6e1a7..0000000000000000000000000000000000000000
--- a/third_party/protobuf/csharp/src/Google.Protobuf/Reflection/DescriptorUtil.cs
+++ /dev/null
@@ -1,64 +0,0 @@
-#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
-// 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.Collections.Generic;
-using System.Collections.ObjectModel;
-
-namespace Google.Protobuf.Reflection
-{
-    /// <summary>
-    /// Internal class containing utility methods when working with descriptors.
-    /// </summary>
-    internal static class DescriptorUtil
-    {
-        /// <summary>
-        /// Equivalent to Func[TInput, int, TOutput] but usable in .NET 2.0. Only used to convert
-        /// arrays.
-        /// </summary>
-        internal delegate TOutput IndexedConverter<TInput, TOutput>(TInput element, int index);
-
-        /// <summary>
-        /// Converts the given array into a read-only list, applying the specified conversion to
-        /// each input element.
-        /// </summary>
-        internal static IList<TOutput> ConvertAndMakeReadOnly<TInput, TOutput>
-            (IList<TInput> input, IndexedConverter<TInput, TOutput> converter)
-        {
-            TOutput[] array = new TOutput[input.Count];
-            for (int i = 0; i < array.Length; i++)
-            {
-                array[i] = converter(input[i], i);
-            }
-            return new ReadOnlyCollection<TOutput>(array);
-        }
-    }
-}