Standardize usage of virtual/override/final in net/

net/dns/host_resolver_impl.cc

Index: net/dns/host_resolver_impl.cc
diff --git a/net/dns/host_resolver_impl.cc b/net/dns/host_resolver_impl.cc
index 5632ef9d5ba51f3392215892ce8be36ab355c471..8913f17fd762c61e6d709cc497521764fe3cd2c0 100644
--- a/net/dns/host_resolver_impl.cc
+++ b/net/dns/host_resolver_impl.cc
@@ -1221,7 +1221,7 @@ class HostResolverImpl::Job : public PrioritizedDispatcher::Job,
                    &key_.hostname));
   }
 
-  virtual ~Job() {
+  ~Job() override {
     if (is_running()) {
       // |resolver_| was destroyed with this Job still in flight.
       // Clean-up, record in the log, but don't run any callbacks.
@@ -1424,7 +1424,7 @@ class HostResolverImpl::Job : public PrioritizedDispatcher::Job,
   }
 
   // PriorityDispatch::Job:
-  virtual void Start() override {
+  void Start() override {
     DCHECK_LE(num_occupied_job_slots_, 1u);
 
     handle_.Reset();
@@ -1587,10 +1587,10 @@ class HostResolverImpl::Job : public PrioritizedDispatcher::Job,
 
   // HostResolverImpl::DnsTask::Delegate implementation:
 
-  virtual void OnDnsTaskComplete(base::TimeTicks start_time,
-                                 int net_error,
-                                 const AddressList& addr_list,
-                                 base::TimeDelta ttl) override {
+  void OnDnsTaskComplete(base::TimeTicks start_time,
+                         int net_error,
+                         const AddressList& addr_list,
+                         base::TimeDelta ttl) override {
     DCHECK(is_dns_running());
 
     base::TimeDelta duration = base::TimeTicks::Now() - start_time;
@@ -1625,7 +1625,7 @@ class HostResolverImpl::Job : public PrioritizedDispatcher::Job,
         bounded_ttl);
   }
 
-  virtual void OnFirstDnsTransactionComplete() override {
+  void OnFirstDnsTransactionComplete() override {
     DCHECK(dns_task_->needs_two_transactions());
     DCHECK_EQ(dns_task_->needs_another_transaction(), is_queued());
     // No longer need to occupy two dispatcher slots.