third_party/protobuf: Update to HEAD (83d681ee2c)

third_party/protobuf/python/google/protobuf/internal/any_test.proto

 // 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.
@@ skipping 12 matching lines @@
 // 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.
 
 // Author: jieluo@google.com (Jie Luo)
 
-syntax = "proto3";
+syntax = "proto2";
 
 package google.protobuf.internal;
 
 import "google/protobuf/any.proto";
 
 message TestAny {
-  google.protobuf.Any value = 1;
-  int32 int_value = 2;
+  optional google.protobuf.Any value = 1;
+  optional int32 int_value = 2;
+  extensions 10 to max;
 }
+
+message TestAnyExtension1 {
+  extend TestAny {
+    optional TestAnyExtension1 extension1 = 98418603;
+  }
+  optional int32 i = 15;
+}