Fix crash on IP address change.

net/base/mock_host_resolver.h

Index: net/base/mock_host_resolver.h
diff --git a/net/base/mock_host_resolver.h b/net/base/mock_host_resolver.h
index ff9f9fc815c1b67b6c2766424345b2f3d5d0e309..5a1df7f716b78bd46d8298b7a5b8ecfdac3e10de 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;