Update //third_party/protobuf to version 3.

third_party/protobuf/src/google/protobuf/util/internal/testdata/maps.proto

Index: third_party/protobuf/src/google/protobuf/util/internal/testdata/maps.proto
diff --git a/third_party/protobuf/src/google/protobuf/unittest_no_generic_services.proto b/third_party/protobuf/src/google/protobuf/util/internal/testdata/maps.proto
similarity index 75%
copy from third_party/protobuf/src/google/protobuf/unittest_no_generic_services.proto
copy to third_party/protobuf/src/google/protobuf/util/internal/testdata/maps.proto
index cffb4122c5c4f9d2e63a09d70c3784614617d88d..7fb42a2628811d2040eafd1adf4d810b2eaab03f 100644
--- a/third_party/protobuf/src/google/protobuf/unittest_no_generic_services.proto
+++ b/third_party/protobuf/src/google/protobuf/util/internal/testdata/maps.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
@@ -28,25 +28,30 @@
 // (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: kenton@google.com (Kenton Varda)
+// Proto to test proto3 maps.
+syntax = "proto3";
 
-package google.protobuf.no_generic_services_test;
+package google.protobuf.testing.maps;
+option java_package = "com.google.protobuf.testing.maps";
 
-// *_generic_services are false by default.
-
-message TestMessage {
-  optional int32 a = 1;
-  extensions 1000 to max;
+message MapIn {
+  string other = 1;
+  repeated string things = 2;
+  map<string, string> map_input = 3;
 }
 
-enum TestEnum {
-  FOO = 1;
+message MapOut {
+  map<string, MapM> map1 = 1;
+  map<string, MapOut> map2 = 2;
+  map<int32, string> map3 = 3;
+  string bar = 4;
 }
 
-extend TestMessage {
-  optional int32 test_extension = 1000;
+message MapM {
+  string foo = 1;
 }
 
 service TestService {
-  rpc Foo(TestMessage) returns(TestMessage);
+  rpc Call1(MapIn) returns (MapOut);
+  rpc Call2(MapIn) returns (MapOut);
 }