* Avoid doing concurrent DNS resolves of the same hostname in HostResolver.

* Add a 1 minute cache for host resolves.

* Refactor HostResolver to handle multiple requests.

* Make HostResolver a dependency of URLRequestContext. operate the HostResolver
in async mode for proxy resolver (bridging to IO thread).

TEST=unittests
BUG=13163

Review URL: http://codereview.chromium.org/118100

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@18236 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 9 insertions, 3 deletions

diff --git a/net/http/http_network_layer.h b/net/http/http_network_layer.h
index 2011a6c..acee57e 100644
--- a/net/http/http_network_layer.h
+++ b/net/http/http_network_layer.h
@@ -11,14 +11,16 @@
 
 namespace net {
 
+class HostResolver;
 class HttpNetworkSession;
 class ProxyInfo;
 class ProxyService;
 
 class HttpNetworkLayer : public HttpTransactionFactory {
  public:
-  // |proxy_service| must remain valid for the lifetime of HttpNetworkLayer.
-  explicit HttpNetworkLayer(ProxyService* proxy_service);
+  // |proxy_service| and |host_resolver| must remain valid for the lifetime of
+  // HttpNetworkLayer.
+  HttpNetworkLayer(HostResolver* host_resolver, ProxyService* proxy_service);
   // Construct a HttpNetworkLayer with an existing HttpNetworkSession which
   // contains a valid ProxyService.
   explicit HttpNetworkLayer(HttpNetworkSession* session);
@@ -26,7 +28,8 @@ class HttpNetworkLayer : public HttpTransactionFactory {
 
   // This function hides the details of how a network layer gets instantiated
   // and allows other implementations to be substituted.
-  static HttpTransactionFactory* CreateFactory(ProxyService* proxy_service);
+  static HttpTransactionFactory* CreateFactory(HostResolver* host_resolver,
+                                               ProxyService* proxy_service);
   // Create a transaction factory that instantiate a network layer over an
   // existing network session. Network session contains some valuable
   // information (e.g. authentication data) that we want to share across
@@ -43,6 +46,9 @@ class HttpNetworkLayer : public HttpTransactionFactory {
   HttpNetworkSession* GetSession();
 
  private:
+  // The host resolver being used for the session.
+  HostResolver* host_resolver_;
+
   // The proxy service being used for the session.
   ProxyService* proxy_service_;