Update //third_party/protobuf to version 3.

third_party/protobuf/src/google/protobuf/unittest_preserve_unknown_enum.proto

Index: third_party/protobuf/src/google/protobuf/unittest_preserve_unknown_enum.proto
diff --git a/third_party/protobuf/python/google/protobuf/internal/factory_test1.proto b/third_party/protobuf/src/google/protobuf/unittest_preserve_unknown_enum.proto
similarity index 63%
copy from third_party/protobuf/python/google/protobuf/internal/factory_test1.proto
copy to third_party/protobuf/src/google/protobuf/unittest_preserve_unknown_enum.proto
index 9f55e037f6e69ff8e76a3f260eff006af1bcce65..2f91332c9e7faa7f592b8636f8129ed5edb72535 100644
--- a/third_party/protobuf/python/google/protobuf/internal/factory_test1.proto
+++ b/third_party/protobuf/src/google/protobuf/unittest_preserve_unknown_enum.proto
@@ -1,6 +1,6 @@
 // Protocol Buffers - Google's data interchange format
 // Copyright 2008 Google Inc.  All rights reserved.
-// http://code.google.com/p/protobuf/
+// 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
@@ -28,28 +28,44 @@
 // (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: matthewtoia@google.com (Matt Toia)
+syntax = "proto3";
 
+package proto3_preserve_unknown_enum_unittest;
+option objc_class_prefix = "UnknownEnums";
 
-package google.protobuf.python.internal;
+option csharp_namespace = "Google.Protobuf.TestProtos";
 
+enum MyEnum {
+  FOO = 0;
+  BAR = 1;
+  BAZ = 2;
+}
 
-enum Factory1Enum {
-  FACTORY_1_VALUE_0 = 0;
-  FACTORY_1_VALUE_1 = 1;
+enum MyEnumPlusExtra {
+  E_FOO = 0;
+  E_BAR = 1;
+  E_BAZ = 2;
+  E_EXTRA = 3;
 }
 
-message Factory1Message {
-  optional Factory1Enum factory_1_enum = 1;
-  enum NestedFactory1Enum {
-    NESTED_FACTORY_1_VALUE_0 = 0;
-    NESTED_FACTORY_1_VALUE_1 = 1;
+message MyMessage {
+  MyEnum e = 1;
+  repeated MyEnum repeated_e = 2;
+  repeated MyEnum repeated_packed_e = 3 [packed=true];
+  repeated MyEnumPlusExtra repeated_packed_unexpected_e = 4;  // not packed
+  oneof o {
+    MyEnum oneof_e_1 = 5;
+    MyEnum oneof_e_2 = 6;
   }
-  optional NestedFactory1Enum nested_factory_1_enum = 2;
-  message NestedFactory1Message {
-    optional string value = 1;
+}
+
+message MyMessagePlusExtra {
+  MyEnumPlusExtra e = 1;
+  repeated MyEnumPlusExtra repeated_e = 2;
+  repeated MyEnumPlusExtra repeated_packed_e = 3 [packed=true];
+  repeated MyEnumPlusExtra repeated_packed_unexpected_e = 4 [packed=true];
+  oneof o {
+    MyEnumPlusExtra oneof_e_1 = 5;
+    MyEnumPlusExtra oneof_e_2 = 6;
   }
-  optional NestedFactory1Message nested_factory_1_message = 3;
-  optional int32 scalar_value = 4;
-  repeated string list_value = 5;
 }