Update //third_party/protobuf to version 3.

third_party/protobuf/java/src/test/java/com/google/protobuf/map_initialization_order_test.proto

Index: third_party/protobuf/java/src/test/java/com/google/protobuf/map_initialization_order_test.proto
diff --git a/third_party/protobuf/src/google/protobuf/unittest_optimize_for.proto b/third_party/protobuf/java/src/test/java/com/google/protobuf/map_initialization_order_test.proto
similarity index 62%
copy from third_party/protobuf/src/google/protobuf/unittest_optimize_for.proto
copy to third_party/protobuf/java/src/test/java/com/google/protobuf/map_initialization_order_test.proto
index feecbef8d4a90961b35be988402e49e74fed313c..b02ac599a5ed6387a46215393b4014d4bc70ea0d 100644
--- a/third_party/protobuf/src/google/protobuf/unittest_optimize_for.proto
+++ b/third_party/protobuf/java/src/test/java/com/google/protobuf/map_initialization_order_test.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
@@ -28,34 +28,34 @@
 // (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)
-//  Based on original Protocol Buffers design by
-//  Sanjay Ghemawat, Jeff Dean, and others.
-//
-// A proto file which uses optimize_for = CODE_SIZE.
-
-import "google/protobuf/unittest.proto";
+// Regression test for a map initilaization order bug. The bug only manifests
+// when:
+//   1. A message contains map fields and is also extendable.
+//   2. There is a file-level extension defined in the same file referencing
+//      the above message as the extension type.
+//   3. The program executes in the following order:
+//        a. getDescriptor() is called on another message in the same file.
+//        b. use protobuf reflection to access the map field.
+// The symptom is a NullPointerException being thrown.
+syntax = "proto2";
 
-package protobuf_unittest;
+package map_test;
 
-option optimize_for = CODE_SIZE;
+option java_package = "map_test";
+option java_outer_classname = "MapInitializationOrderTest";
+option java_multiple_files = true;
 
-message TestOptimizedForSize {
-  optional int32 i = 1;
-  optional ForeignMessage msg = 19;
+// Mirrors the structure of
+// javatests/com/google/cloud/common/logging/logging_test.proto.
 
+message Message1 {
+  map<string, bool> map_field = 1;
   extensions 1000 to max;
-
-  extend TestOptimizedForSize {
-    optional int32 test_extension = 1234;
-    optional TestRequiredOptimizedForSize test_extension2 = 1235;
-  }
 }
 
-message TestRequiredOptimizedForSize {
-  required int32 x = 1;
+extend Message1 {
+  optional Message1 recursive_extension = 1001;
 }
- 
-message TestOptionalOptimizedForSize {
-  optional TestRequiredOptimizedForSize o = 1;
+
+message RedactAllTypes {
 }