7 files changed, 44 insertions, 15 deletions
diff --git a/net/base/host_resolver.h b/net/base/host_resolver.h
index 9fd8dbe4..e4bf847 100644
--- a/net/base/host_resolver.h
+++ b/net/base/host_resolver.h
@@ -167,9 +167,6 @@ class HostResolver : public base::RefCountedThreadSafe<HostResolver> {
   // Unregisters an observer previously added by AddObserver().
   virtual void RemoveObserver(Observer* observer) = 0;
 
-  // Gives the HostResolver an opportunity to flush state.
-  virtual void Flush() {}
-
   // Sets the default AddressFamily to use when requests have left it
   // unspecified. For example, this could be used to restrict resolution
   // results to AF_INET by passing in ADDRESS_FAMILY_IPV4, or to
diff --git a/net/base/host_resolver_impl.cc b/net/base/host_resolver_impl.cc
index 1f43c60..df5bc79 100644
--- a/net/base/host_resolver_impl.cc
+++ b/net/base/host_resolver_impl.cc
@@ -683,6 +683,8 @@ HostResolverImpl::HostResolverImpl(
 #if defined(OS_WIN)
   EnsureWinsockInit();
 #endif
+  if (network_change_notifier_)
+    network_change_notifier_->AddObserver(this);
 }
 
 HostResolverImpl::~HostResolverImpl() {
@@ -697,6 +699,9 @@ HostResolverImpl::~HostResolverImpl() {
   if (cur_completing_job_)
     cur_completing_job_->Cancel();
 
+  if (network_change_notifier_)
+    network_change_notifier_->RemoveObserver(this);
+
   // Delete the job pools.
   for (size_t i = 0u; i < arraysize(job_pools_); ++i)
     delete job_pools_[i];
@@ -841,7 +846,7 @@ void HostResolverImpl::SetDefaultAddressFamily(AddressFamily address_family) {
 void HostResolverImpl::ProbeIPv6Support() {
   DCHECK(!ipv6_probe_monitoring_);
   ipv6_probe_monitoring_ = true;
-  Flush();  // Give initial setup call.
+  OnIPAddressChanged();  // Give initial setup call.
 }
 
 void HostResolverImpl::Shutdown() {
@@ -1074,7 +1079,7 @@ void HostResolverImpl::OnCancelRequest(const BoundNetLog& net_log,
   net_log.EndEvent(NetLog::TYPE_HOST_RESOLVER_IMPL);
 }
 
-void HostResolverImpl::Flush() {
+void HostResolverImpl::OnIPAddressChanged() {
   if (cache_.get())
     cache_->clear();
   if (ipv6_probe_monitoring_) {
diff --git a/net/base/host_resolver_impl.h b/net/base/host_resolver_impl.h
index 4814921..1a182b3 100644
--- a/net/base/host_resolver_impl.h
+++ b/net/base/host_resolver_impl.h
@@ -47,7 +47,8 @@ namespace net {
 //
 // Requests are ordered in the queue based on their priority.
 
-class HostResolverImpl : public HostResolver {
+class HostResolverImpl : public HostResolver,
+                         public NetworkChangeNotifier::Observer {
  public:
   // The index into |job_pools_| for the various job pools. Pools with a higher
   // index have lower priority.
@@ -87,7 +88,6 @@ class HostResolverImpl : public HostResolver {
   virtual void CancelRequest(RequestHandle req);
   virtual void AddObserver(HostResolver::Observer* observer);
   virtual void RemoveObserver(HostResolver::Observer* observer);
-  virtual void Flush();
 
   // Set address family, and disable IPv6 probe support.
   virtual void SetDefaultAddressFamily(AddressFamily address_family);
@@ -180,6 +180,9 @@ class HostResolverImpl : public HostResolver {
                        int request_id,
                        const RequestInfo& info);
 
+  // NetworkChangeNotifier::Observer methods:
+  virtual void OnIPAddressChanged();
+
   // Notify IPv6ProbeJob not to call back, and discard reference to the job.
   void DiscardIPv6ProbeJob();
 
diff --git a/net/base/host_resolver_impl_unittest.cc b/net/base/host_resolver_impl_unittest.cc
index e9a721c..a17fb6a 100644
--- a/net/base/host_resolver_impl_unittest.cc
+++ b/net/base/host_resolver_impl_unittest.cc
@@ -1043,6 +1043,38 @@ TEST_F(HostResolverImplTest, CancellationObserver) {
               CapturingObserver::StartOrCancelEntry(1, info));
 }
 
+// Test that IP address changes flush the cache.
+TEST_F(HostResolverImplTest, FlushCacheOnIPAddressChange) {
+  MockNetworkChangeNotifier mock_network_change_notifier;
+  scoped_refptr<HostResolver> host_resolver(
+      new HostResolverImpl(NULL, CreateDefaultCache(),
+                           &mock_network_change_notifier,
+                           kMaxJobs));
+
+  AddressList addrlist;
+
+  // Resolve "host1".
+  HostResolver::RequestInfo info1("host1", 70);
+  TestCompletionCallback callback;
+  int rv = host_resolver->Resolve(info1, &addrlist, &callback, NULL, NULL);
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback.WaitForResult());
+
+  // Resolve "host1" again -- this time it will be served from cache, but it
+  // should still notify of completion.
+  rv = host_resolver->Resolve(info1, &addrlist, &callback, NULL, NULL);
+  ASSERT_EQ(OK, rv);  // Should complete synchronously.
+
+  // Flush cache by triggering an IP address change.
+  mock_network_change_notifier.NotifyIPAddressChange();
+
+  // Resolve "host1" again -- this time it won't be served from cache, so it
+  // will complete asynchronously.
+  rv = host_resolver->Resolve(info1, &addrlist, &callback, NULL, NULL);
+  ASSERT_EQ(ERR_IO_PENDING, rv);  // Should complete asynchronously.
+  EXPECT_EQ(OK, callback.WaitForResult());
+}
+
 // Tests that when the maximum threads is set to 1, requests are dequeued
 // in order of priority.
 TEST_F(HostResolverImplTest, HigherPriorityRequestsStartedFirst) {
diff --git a/net/base/mapped_host_resolver.h b/net/base/mapped_host_resolver.h
index 890f3072..7339f06 100644
--- a/net/base/mapped_host_resolver.h
+++ b/net/base/mapped_host_resolver.h
@@ -32,7 +32,6 @@ class MappedHostResolver : public HostResolver {
   virtual void CancelRequest(RequestHandle req);
   virtual void AddObserver(Observer* observer);
   virtual void RemoveObserver(Observer* observer);
-  virtual void Flush() { impl_->Flush(); }
   virtual HostResolverImpl* GetAsHostResolverImpl();
 
   // Adds a rule to this mapper. The format of the rule can be one of:
diff --git a/net/base/mock_host_resolver.cc b/net/base/mock_host_resolver.cc
index 9e57fd1..d99b24e 100644
--- a/net/base/mock_host_resolver.cc
+++ b/net/base/mock_host_resolver.cc
@@ -66,10 +66,6 @@ void MockHostResolverBase::RemoveObserver(Observer* observer) {
   impl_->RemoveObserver(observer);
 }
 
-void MockHostResolverBase::Flush() {
-  impl_->Flush();
-}
-
 void MockHostResolverBase::Reset(HostResolverProc* interceptor) {
   synchronous_mode_ = false;
 
diff --git a/net/base/mock_host_resolver.h b/net/base/mock_host_resolver.h
index ff9f9fc..5a1df7f 100644
--- a/net/base/mock_host_resolver.h
+++ b/net/base/mock_host_resolver.h
@@ -47,12 +47,9 @@ class MockHostResolverBase : public HostResolver {
   virtual void CancelRequest(RequestHandle req);
   virtual void AddObserver(Observer* observer);
   virtual void RemoveObserver(Observer* observer);
-  virtual void Flush();
 
   RuleBasedHostResolverProc* rules() { return rules_; }
 
-  const HostCache* cache() const { return impl_->cache(); }
-
   // Controls whether resolutions complete synchronously or asynchronously.
   void set_synchronous_mode(bool is_synchronous) {
     synchronous_mode_ = is_synchronous;