Modify ALLOW_UNUSED to allow enabling unused local warnings on MSVC.

base/logging_unittest.cc

Index: base/logging_unittest.cc
diff --git a/base/logging_unittest.cc b/base/logging_unittest.cc
index 6ebe32e432aa06374645477badb59a2b2b5fd09f..95a16f2e4bb12d0857812a57dadf955ac2cf0a6c 100644
--- a/base/logging_unittest.cc
+++ b/base/logging_unittest.cc
@@ -240,7 +240,8 @@ TEST_F(LoggingTest, DcheckReleaseBehavior) {
 // looking in the global namespace.
 namespace nested_test {
   class Streamable {};
-  ALLOW_UNUSED std::ostream& operator<<(std::ostream& out, const Streamable&) {
+  ALLOW_UNUSED_TYPE std::ostream& operator<<(std::ostream& out,
+                                             const Streamable&) {
     return out << "Streamable";
   }
   TEST_F(LoggingTest, StreamingWstringFindsCorrectOperator) {