AsyncHostResolver: integrated HostCache, temporarily, until we have RR cache.

net/base/host_cache.cc

Index: net/base/host_cache.cc
diff --git a/net/base/host_cache.cc b/net/base/host_cache.cc
index 28173d273f164c58e71de244011ea4e1a0887bb8..03eb23a01c1c97e65a3da0916041073d082eec19 100644
--- a/net/base/host_cache.cc
+++ b/net/base/host_cache.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
@@ -117,6 +117,18 @@ bool HostCache::CanUseEntry(const Entry* entry, const base::TimeTicks now) {
   return entry->expiration > now;
 }
 
+// static
+HostCache* HostCache::CreateDefaultCache() {
+  static const size_t kMaxHostCacheEntries = 100;
+
+  HostCache* cache = new HostCache(
+      kMaxHostCacheEntries,
+      base::TimeDelta::FromMinutes(1),
+      base::TimeDelta::FromSeconds(0));  // Disable caching of failed DNS.
+
+  return cache;
+}
+
 void HostCache::Compact(base::TimeTicks now, const Entry* pinned_entry) {
   // Clear out expired entries.
   for (EntryMap::iterator it = entries_.begin(); it != entries_.end(); ) {