Update //third_party/protobuf to version 3.

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

Index: third_party/protobuf/java/src/test/java/com/google/protobuf/test_extra_interfaces.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/test_extra_interfaces.proto
similarity index 65%
copy from third_party/protobuf/src/google/protobuf/unittest_optimize_for.proto
copy to third_party/protobuf/java/src/test/java/com/google/protobuf/test_extra_interfaces.proto
index feecbef8d4a90961b35be988402e49e74fed313c..645f57b4bb43f1382a02b1a53af76e7b213fca50 100644
--- a/third_party/protobuf/src/google/protobuf/unittest_optimize_for.proto
+++ b/third_party/protobuf/java/src/test/java/com/google/protobuf/test_extra_interfaces.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";
+// Author: Darick Tong (darick@google.com)
+syntax = "proto2";
 
 package protobuf_unittest;
 
-option optimize_for = CODE_SIZE;
+message Proto1 {
+  option experimental_java_message_interface =
+      "com.google.protobuf.ExtraInterfaces.HasBoolValue";
 
-message TestOptimizedForSize {
-  optional int32 i = 1;
-  optional ForeignMessage msg = 19;
+  option experimental_java_interface_extends =
+      "com.google.protobuf.ExtraInterfaces.HasByteValue";
 
-  extensions 1000 to max;
+  option experimental_java_message_interface =
+      "com.google.protobuf.ExtraInterfaces.HasStringValue<Proto1>";
 
-  extend TestOptimizedForSize {
-    optional int32 test_extension = 1234;
-    optional TestRequiredOptimizedForSize test_extension2 = 1235;
-  }
-}
+  option experimental_java_builder_interface =
+      "com.google.protobuf.ExtraInterfaces.HasStringValueBuilder"
+      "<Proto1, Builder>";
 
-message TestRequiredOptimizedForSize {
-  required int32 x = 1;
+  optional string string_value = 1;
+  optional bool bool_value = 2;
+  optional bytes byte_value = 3;
+  optional int32 int_value = 4;
 }
- 
-message TestOptionalOptimizedForSize {
-  optional TestRequiredOptimizedForSize o = 1;
+
+message Proto2 {
+  option experimental_java_message_interface =
+      "com.google.protobuf.ExtraInterfaces.HasBoolValue";
+
+  optional bool bool_value = 1;
 }