Fix uninitialized reads in DnsConfigServiceWin tests.

net/dns/dns_config_service_win.h

Index: net/dns/dns_config_service_win.h
diff --git a/net/dns/dns_config_service_win.h b/net/dns/dns_config_service_win.h
index 5b6f22bb7de4b77b545fc22de1f37c3f8fa3bede..61c3ccb94da13ccf8268b5c0b3d1e9fd227a079d 100644
--- a/net/dns/dns_config_service_win.h
+++ b/net/dns/dns_config_service_win.h
@@ -47,12 +47,12 @@ bool NET_EXPORT_PRIVATE ParseSearchList(const base::string16& value,
 struct NET_EXPORT_PRIVATE DnsSystemSettings {
   // The |set| flag distinguishes between empty and unset values.
   struct RegString {
-    bool set;
+    bool set = false;
     base::string16 value;
   };
 
   struct RegDword {
-    bool set;
+    bool set = false;
     DWORD value;
   };