Update //third_party/protobuf to version 3.

third_party/protobuf/src/google/protobuf/map_unittest_proto3.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.
+//     * 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.
+
+// This file is mostly equivalent to map_unittest.proto, but imports
+// unittest_proto3.proto instead of unittest.proto, so that it only
+// uses proto3 messages. This makes it suitable for testing
+// implementations which only support proto3.
+// The TestRequiredMessageMap message has been removed as there are no
+// required fields in proto3.
+syntax = "proto3";
+
+option cc_enable_arenas = true;
+option csharp_namespace = "Google.Protobuf.TestProtos";
+
+import "google/protobuf/unittest_proto3.proto";
+
+// We don't put this in a package within proto2 because we need to make sure
+// that the generated code doesn't depend on being in the proto2 namespace.
+// In map_test_util.h we do "using namespace unittest = protobuf_unittest".
+package protobuf_unittest;
+
+// Tests maps.
+message TestMap {
+  map<int32   , int32   > map_int32_int32       = 1;
+  map<int64   , int64   > map_int64_int64       = 2;
+  map<uint32  , uint32  > map_uint32_uint32     = 3;
+  map<uint64  , uint64  > map_uint64_uint64     = 4;
+  map<sint32  , sint32  > map_sint32_sint32     = 5;
+  map<sint64  , sint64  > map_sint64_sint64     = 6;
+  map<fixed32 , fixed32 > map_fixed32_fixed32   = 7;
+  map<fixed64 , fixed64 > map_fixed64_fixed64   = 8;
+  map<sfixed32, sfixed32> map_sfixed32_sfixed32 = 9;
+  map<sfixed64, sfixed64> map_sfixed64_sfixed64 = 10;
+  map<int32   , float   > map_int32_float       = 11;
+  map<int32   , double  > map_int32_double      = 12;
+  map<bool    , bool    > map_bool_bool         = 13;
+  map<string  , string  > map_string_string     = 14;
+  map<int32   , bytes   > map_int32_bytes       = 15;
+  map<int32   , MapEnum > map_int32_enum        = 16;
+  map<int32   , ForeignMessage> map_int32_foreign_message = 17;
+}
+
+message TestMapSubmessage {
+  TestMap test_map = 1;
+}
+
+message TestMessageMap {
+  map<int32, TestAllTypes> map_int32_message = 1;
+}
+
+// Two map fields share the same entry default instance.
+message TestSameTypeMap {
+  map<int32, int32> map1 = 1;
+  map<int32, int32> map2 = 2;
+}
+
+enum MapEnum {
+  MAP_ENUM_FOO = 0;
+  MAP_ENUM_BAR = 1;
+  MAP_ENUM_BAZ = 2;
+}
+
+message TestArenaMap {
+  map<int32   , int32   > map_int32_int32       = 1;
+  map<int64   , int64   > map_int64_int64       = 2;
+  map<uint32  , uint32  > map_uint32_uint32     = 3;
+  map<uint64  , uint64  > map_uint64_uint64     = 4;
+  map<sint32  , sint32  > map_sint32_sint32     = 5;
+  map<sint64  , sint64  > map_sint64_sint64     = 6;
+  map<fixed32 , fixed32 > map_fixed32_fixed32   = 7;
+  map<fixed64 , fixed64 > map_fixed64_fixed64   = 8;
+  map<sfixed32, sfixed32> map_sfixed32_sfixed32 = 9;
+  map<sfixed64, sfixed64> map_sfixed64_sfixed64 = 10;
+  map<int32   , float   > map_int32_float       = 11;
+  map<int32   , double  > map_int32_double      = 12;
+  map<bool    , bool    > map_bool_bool         = 13;
+  map<int32   , MapEnum > map_int32_enum        = 14;
+  map<int32   , ForeignMessage> map_int32_foreign_message = 15;
+}
+
+// Previously, message containing enum called Type cannot be used as value of
+// map field.
+message MessageContainingEnumCalledType {
+  enum Type {
+    TYPE_FOO = 0;
+  }
+  map<int32, MessageContainingEnumCalledType> type = 1;
+}
+
+// Previously, message cannot contain map field called "entry".
+message MessageContainingMapCalledEntry {
+  map<int32, int32> entry = 1;
+}