Deprecate NonThreadSafe in net/ in favor of SequenceChecker/ThreadChecker.

net/dns/dns_transaction.cc

Index: net/dns/dns_transaction.cc
diff --git a/net/dns/dns_transaction.cc b/net/dns/dns_transaction.cc
index 8c7a757724096773e40e90d5178c981f9cdfaee9..2ec93d0443be40205f8f9d871a66fe81c5ec4d55 100644
--- a/net/dns/dns_transaction.cc
+++ b/net/dns/dns_transaction.cc
@@ -20,10 +20,10 @@
 #include "base/metrics/histogram_macros.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/rand_util.h"
+#include "base/sequence_checker.h"
 #include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/string_piece.h"
-#include "base/threading/non_thread_safe.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/timer/timer.h"
 #include "base/values.h"
@@ -559,7 +559,6 @@ class DnsTCPAttempt : public DnsAttempt {
 // DnsSession::NextFirstServerIndex, and the order is round-robin afterwards.
 // Each server is attempted DnsConfig::attempts times.
 class DnsTransactionImpl : public DnsTransaction,
-                           public base::NonThreadSafe,
                            public base::SupportsWeakPtr<DnsTransactionImpl> {
  public:
   DnsTransactionImpl(DnsSession* session,
@@ -583,6 +582,7 @@ class DnsTransactionImpl : public DnsTransaction,
   }
 
   ~DnsTransactionImpl() override {
+    DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
     if (!callback_.is_null()) {
       net_log_.EndEventWithNetErrorCode(NetLogEventType::DNS_TRANSACTION,
                                         ERR_ABORTED);
@@ -590,12 +590,12 @@ class DnsTransactionImpl : public DnsTransaction,
   }
 
   const std::string& GetHostname() const override {
-    DCHECK(CalledOnValidThread());
+    DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
     return hostname_;
   }
 
   uint16_t GetType() const override {
-    DCHECK(CalledOnValidThread());
+    DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
     return qtype_;
   }
 
@@ -970,6 +970,8 @@ class DnsTransactionImpl : public DnsTransaction,
 
   base::OneShotTimer timer_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(DnsTransactionImpl);
 };