Pretty print AlternativeService in test macros.

net/http/http_server_properties.h

Index: net/http/http_server_properties.h
diff --git a/net/http/http_server_properties.h b/net/http/http_server_properties.h
index 4192361187cdbb0684d3ceeb56193d4bcb937764..edf93435e036c91fba24de6c20dbd4880f6c938d 100644
--- a/net/http/http_server_properties.h
+++ b/net/http/http_server_properties.h
@@ -5,8 +5,10 @@
 #ifndef NET_HTTP_HTTP_SERVER_PROPERTIES_H_
 #define NET_HTTP_HTTP_SERVER_PROPERTIES_H_
 
+#include <iosfwd>
 #include <map>
 #include <string>
+
 #include "base/basictypes.h"
 #include "base/containers/mru_cache.h"
 #include "base/memory/weak_ptr.h"
@@ -137,6 +139,10 @@ struct NET_EXPORT AlternativeService {
   uint16 port;
 };
 
+NET_EXPORT std::ostream& operator<<(
+    std::ostream& os,
+    const AlternativeService& alternative_service);
+
 struct NET_EXPORT AlternativeServiceInfo {
   AlternativeServiceInfo() : alternative_service(), probability(0.0) {}