Update //third_party/protobuf to version 3.

third_party/protobuf/src/google/protobuf/stubs/stringprintf_unittest.cc

Index: third_party/protobuf/src/google/protobuf/stubs/stringprintf_unittest.cc
diff --git a/third_party/protobuf/src/google/protobuf/stubs/stringprintf_unittest.cc b/third_party/protobuf/src/google/protobuf/stubs/stringprintf_unittest.cc
index a78a2027ca23b1ed225dcefa299c26a8a38955cc..15895e596cdc43f064bbf7283edf7a80377934e2 100644
--- a/third_party/protobuf/src/google/protobuf/stubs/stringprintf_unittest.cc
+++ b/third_party/protobuf/src/google/protobuf/stubs/stringprintf_unittest.cc
@@ -1,6 +1,6 @@
 // Protocol Buffers - Google's data interchange format
 // Copyright 2012 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
@@ -54,8 +54,8 @@ TEST(StringPrintfTest, Empty) {
 }
 
 TEST(StringPrintfTest, Misc) {
-// MSVC does not support $ format specifier.
-#if !defined(_MSC_VER)
+// MSVC and mingw does not support $ format specifier.
+#if !defined(_MSC_VER) && !defined(__MINGW32__)
   EXPECT_EQ("123hello w", StringPrintf("%3$d%2$s %1$c", 'w', "hello", 123));
 #endif  // !_MSC_VER
 }