Revert "third_party/protobuf: Update to HEAD (83d681ee2c)"

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

Index: third_party/protobuf/csharp/src/Google.Protobuf/Reflection/FileDescriptor.cs
diff --git a/third_party/protobuf/csharp/src/Google.Protobuf/Reflection/FileDescriptor.cs b/third_party/protobuf/csharp/src/Google.Protobuf/Reflection/FileDescriptor.cs
index 94efea9e60b1d4fed3c0bb0b9b1436468e2d9ae1..ab7cd92216e06cadb2bb157d85ca1c90caa41696 100644
--- a/third_party/protobuf/csharp/src/Google.Protobuf/Reflection/FileDescriptor.cs
+++ b/third_party/protobuf/csharp/src/Google.Protobuf/Reflection/FileDescriptor.cs
@@ -251,6 +251,17 @@ namespace Google.Protobuf.Reflection
                     "Dependencies passed to FileDescriptor.BuildFrom() don't match " +
                     "those listed in the FileDescriptorProto.");
             }
+            for (int i = 0; i < proto.Dependency.Count; i++)
+            {
+                if (dependencies[i].Name != proto.Dependency[i])
+                {
+                    throw new DescriptorValidationException(
+                        result,
+                        "Dependencies passed to FileDescriptor.BuildFrom() don't match " +
+                        "those listed in the FileDescriptorProto. Expected: " +
+                        proto.Dependency[i] + " but was: " + dependencies[i].Name);
+                }
+            }
 
             result.CrossLink();
             return result;
@@ -330,4 +341,4 @@ namespace Google.Protobuf.Reflection
         /// </value>
         public static FileDescriptor DescriptorProtoFileDescriptor { get { return DescriptorReflection.Descriptor; } }
     }
-}
+}