Add embedder-specific headers to HTTP CONNECT tunnel request

net/socket/client_socket_pool_manager_impl.h

Index: net/socket/client_socket_pool_manager_impl.h
diff --git a/net/socket/client_socket_pool_manager_impl.h b/net/socket/client_socket_pool_manager_impl.h
index 8fc6c49ef8439ccf36aaee2ed10650a2f3c7b6b8..24d41352c30e1f60f21c4ad420ec77dbae2037cd 100644
--- a/net/socket/client_socket_pool_manager_impl.h
+++ b/net/socket/client_socket_pool_manager_impl.h
@@ -7,6 +7,7 @@
 
 #include <map>
 #include "base/basictypes.h"
+#include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ -68,6 +69,9 @@ class ClientSocketPoolManagerImpl : public base::NonThreadSafe,
                               ProxyService* proxy_service,
                               SSLConfigService* ssl_config_service,
                               bool enable_ssl_connect_job_waiting,
+                              const base::Callback<void(const HostPortPair&,
+                                                        HttpRequestHeaders*)>&
+                                  before_proxy_tunnel_request_callback,
                               HttpNetworkSession::SocketPoolType pool_type);
   virtual ~ClientSocketPoolManagerImpl();
 
@@ -147,6 +151,9 @@ class ClientSocketPoolManagerImpl : public base::NonThreadSafe,
   ClientSocketPoolHistograms ssl_socket_pool_for_proxies_histograms_;
   SSLSocketPoolMap ssl_socket_pools_for_proxies_;
 
+  base::Callback<void(const HostPortPair&, HttpRequestHeaders*)>
+      before_proxy_tunnel_request_callback_;
+
   DISALLOW_COPY_AND_ASSIGN(ClientSocketPoolManagerImpl);
 };