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

third_party/protobuf/csharp/src/Google.Protobuf/Reflection/MethodDescriptor.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
-// 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
-
-namespace Google.Protobuf.Reflection
-{
-    /// <summary>
-    /// Describes a single method in a service.
-    /// </summary>
-    public sealed class MethodDescriptor : DescriptorBase
-    {
-        private readonly MethodDescriptorProto proto;
-        private readonly ServiceDescriptor service;
-        private MessageDescriptor inputType;
-        private MessageDescriptor outputType;
-
-        /// <value>
-        /// The service this method belongs to.
-        /// </value>
-        public ServiceDescriptor Service { get { return service; } }
-
-        /// <value>
-        /// The method's input type.
-        /// </value>
-        public MessageDescriptor InputType { get { return inputType; } }
-
-        /// <value>
-        /// The method's input type.
-        /// </value>
-        public MessageDescriptor OutputType { get { return outputType; } }
-
-        /// <value>
-        /// Indicates if client streams multiple requests.
-        /// </value>
-        public bool IsClientStreaming { get { return proto.ClientStreaming; } }
-
-        /// <value>
-        /// Indicates if server streams multiple responses.
-        /// </value>
-        public bool IsServerStreaming { get { return proto.ServerStreaming; } }
-
-        internal MethodDescriptor(MethodDescriptorProto proto, FileDescriptor file,
-                                  ServiceDescriptor parent, int index)
-            : base(file, parent.FullName + "." + proto.Name, index)
-        {
-            this.proto = proto;
-            service = parent;
-            file.DescriptorPool.AddSymbol(this);
-        }
-
-        internal MethodDescriptorProto Proto { get { return proto; } }
-
-        /// <summary>
-        /// The brief name of the descriptor's target.
-        /// </summary>
-        public override string Name { get { return proto.Name; } }
-
-        internal void CrossLink()
-        {
-            IDescriptor lookup = File.DescriptorPool.LookupSymbol(Proto.InputType, this);
-            if (!(lookup is MessageDescriptor))
-            {
-                throw new DescriptorValidationException(this, "\"" + Proto.InputType + "\" is not a message type.");
-            }
-            inputType = (MessageDescriptor) lookup;
-
-            lookup = File.DescriptorPool.LookupSymbol(Proto.OutputType, this);
-            if (!(lookup is MessageDescriptor))
-            {
-                throw new DescriptorValidationException(this, "\"" + Proto.OutputType + "\" is not a message type.");
-            }
-            outputType = (MessageDescriptor) lookup;
-        }
-    }
-}