Revert 129277 - Revert 127893 - Attempting to re-land the feature.

net/http/http_proxy_client_socket_pool.h

Index: net/http/http_proxy_client_socket_pool.h
===================================================================
--- net/http/http_proxy_client_socket_pool.h	(revision 129292)
+++ net/http/http_proxy_client_socket_pool.h	(working copy)
@@ -170,7 +170,9 @@
   DISALLOW_COPY_AND_ASSIGN(HttpProxyConnectJob);
 };
 
-class NET_EXPORT_PRIVATE HttpProxyClientSocketPool : public ClientSocketPool {
+class NET_EXPORT_PRIVATE HttpProxyClientSocketPool
+    : public ClientSocketPool,
+      public LayeredPool {
  public:
   HttpProxyClientSocketPool(
       int max_sockets,
@@ -205,6 +207,8 @@
 
   virtual void Flush() OVERRIDE;
 
+  virtual bool IsStalled() const OVERRIDE;
+
   virtual void CloseIdleSockets() OVERRIDE;
 
   virtual int IdleSocketCount() const OVERRIDE;
@@ -216,6 +220,10 @@
       const std::string& group_name,
       const ClientSocketHandle* handle) const OVERRIDE;
 
+  virtual void AddLayeredPool(LayeredPool* layered_pool) OVERRIDE;
+
+  virtual void RemoveLayeredPool(LayeredPool* layered_pool) OVERRIDE;
+
   virtual base::DictionaryValue* GetInfoAsValue(
       const std::string& name,
       const std::string& type,
@@ -225,6 +233,9 @@
 
   virtual ClientSocketPoolHistograms* histograms() const OVERRIDE;
 
+  // LayeredPool implementation.
+  virtual bool CloseOneIdleConnection() OVERRIDE;
+
  private:
   typedef ClientSocketPoolBase<HttpProxySocketParams> PoolBase;