Implement host-based deletion for the hostname resolution cache.

net/dns/host_cache.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_DNS_HOST_CACHE_H_
 #define NET_DNS_HOST_CACHE_H_
 
 #include <stddef.h>
 
 #include <functional>
@@ skipping 128 matching lines @@
            base::TimeTicks now,
            base::TimeDelta ttl);
 
   // Marks all entries as stale on account of a network change.
   void OnNetworkChange();
 
   void set_eviction_callback(const EvictionCallback& callback) {
     eviction_callback_ = callback;
   }
 
-  // Empties the cache
+  // Empties the cache.
   void clear();
 
+  // Clears hosts matching |host_filter| from the cache.
+  void ClearForHosts(
+      const base::Callback<bool(const std::string&)>& host_filter);
+
   // Returns the number of entries in the cache.
   size_t size() const;
 
   // Following are used by net_internals UI.
   size_t max_entries() const;
 
   const EntryMap& entries() const { return entries_; }
 
   // Creates a default cache.
   static std::unique_ptr<HostCache> CreateDefaultCache();
@@ skipping 30 matching lines @@
   size_t max_entries_;
   int network_changes_;
   EvictionCallback eviction_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(HostCache);
 };
 
 }  // namespace net
 
 #endif  // NET_DNS_HOST_CACHE_H_