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

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

Index: third_party/protobuf/csharp/src/Google.Protobuf/Reflection/OriginalNameAttribute.cs
diff --git a/third_party/protobuf/csharp/src/Google.Protobuf/Reflection/IDescriptor.cs b/third_party/protobuf/csharp/src/Google.Protobuf/Reflection/OriginalNameAttribute.cs
similarity index 73%
copy from third_party/protobuf/csharp/src/Google.Protobuf/Reflection/IDescriptor.cs
copy to third_party/protobuf/csharp/src/Google.Protobuf/Reflection/OriginalNameAttribute.cs
index 318d58c968a58a35a3ccd45ee1c7b1f0df275546..27f9ab98c324707cddadaea2130e23fdcb023fed 100644
--- a/third_party/protobuf/csharp/src/Google.Protobuf/Reflection/IDescriptor.cs
+++ b/third_party/protobuf/csharp/src/Google.Protobuf/Reflection/OriginalNameAttribute.cs
@@ -1,4 +1,4 @@
-#region Copyright notice and license
+#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/
@@ -30,26 +30,29 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endregion
 
+using System;
+
 namespace Google.Protobuf.Reflection
 {
     /// <summary>
-    /// Interface implemented by all descriptor types.
+    /// Specifies the original name (in the .proto file) of a named element,
+    /// such as an enum value.
     /// </summary>
-    public interface IDescriptor
+    [AttributeUsage(AttributeTargets.Field)]
+    public class OriginalNameAttribute : Attribute
     {
         /// <summary>
-        /// Returns the name of the entity (message, field etc) being described.
-        /// </summary>
-        string Name { get; }
-
-        /// <summary>
-        /// Returns the fully-qualified name of the entity being described.
+        /// The name of the element in the .proto file.
         /// </summary>
-        string FullName { get; }
+        public string Name { get; set; }
 
         /// <summary>
-        /// Returns the descriptor for the .proto file that this entity is part of.
+        /// Constructs a new attribute instance for the given name.
         /// </summary>
-        FileDescriptor File { get; }
-    }    
+        /// <param name="name">The name of the element in the .proto file.</param>
+        public OriginalNameAttribute(string name)
+        {
+            Name = ProtoPreconditions.CheckNotNull(name, nameof(name));
+        }
+    }
 }