Implement SSLClientSocketPool.

net/socket/client_socket_pool_base.h

Index: net/socket/client_socket_pool_base.h
diff --git a/net/socket/client_socket_pool_base.h b/net/socket/client_socket_pool_base.h
index d515ca5755e53cf156191a5a27ecec684de5c8ba..77698ce715df8ed3fe4baf9f3c22521b1116676b 100644
--- a/net/socket/client_socket_pool_base.h
+++ b/net/socket/client_socket_pool_base.h
@@ -90,6 +90,11 @@ class ConnectJob {
 
   virtual LoadState GetLoadState() const = 0;
 
+  // If Connect returns an error (or OnConnectJobComplete reports an error
+  // result) this method will be called, allowing the pool to add
+  // additional error state to the ClientSocketHandle (post late-binding).
+  virtual void GetAdditionalErrorState(ClientSocketHandle* handle) {}
+
  protected:
   void set_socket(ClientSocket* socket);
   ClientSocket* socket() { return socket_.get(); }