third_party/protobuf: update to upstream r371

third_party/protobuf/src/google/protobuf/unittest.proto

Index: third_party/protobuf/src/google/protobuf/unittest.proto
diff --git a/third_party/protobuf/src/google/protobuf/unittest.proto b/third_party/protobuf/src/google/protobuf/unittest.proto
index d51fa1e7fe3bcab218d0fc5fe1f8d99eb5ea4ad2..97ec67475ef9a02d6f1ad4b6f8506813287ffc6a 100644
--- a/third_party/protobuf/src/google/protobuf/unittest.proto
+++ b/third_party/protobuf/src/google/protobuf/unittest.proto
@@ -35,6 +35,12 @@
 // A proto file we will use for unit testing.
 
 
+// Some generic_services option(s) added automatically.
+// See:  http://go/proto2-generic-services-default
+option cc_generic_services = true;     // auto-added
+option java_generic_services = true;   // auto-added
+option py_generic_services = true;     // auto-added
+
 import "google/protobuf/unittest_import.proto";
 
 // We don't put this in a package within proto2 because we need to make sure
@@ -487,6 +493,17 @@ message TestExtremeDefaultValues {
   optional float inf_float = 17 [default = inf];
   optional float neg_inf_float = 18 [default = -inf];
   optional float nan_float = 19 [default = nan];
+
+  // Tests for C++ trigraphs.
+  // Trigraphs should be escaped in C++ generated files, but they should not be
+  // escaped for other languages.
+  // Note that in .proto file, "\?" is a valid way to escape ? in string
+  // literals.
+  optional string cpp_trigraph = 20 [default = "? \? ?? \?? \??? ??/ ?\?-"];
+}
+
+message SparseEnumMessage {
+  optional TestSparseEnum sparse_enum = 1;
 }
 
 // Test String and Bytes: string is for valid UTF-8 strings
@@ -598,6 +615,7 @@ message TestRepeatedScalarDifferentTagSizes {
   repeated uint64  repeated_uint64  = 262143;
 }
 
+
 // Test that RPC services work.
 message FooRequest  {}
 message FooResponse {}