Implementation of network level throttler.

net/http/http_network_session_peer.h

Index: net/http/http_network_session_peer.h
diff --git a/net/http/http_network_session_peer.h b/net/http/http_network_session_peer.h
index da057f06ab9e25cbce7423cdb0885aa8de0fba02..c58eb1644071211547c0c2d95226e7983a3cd24e 100644
--- a/net/http/http_network_session_peer.h
+++ b/net/http/http_network_session_peer.h
@@ -16,6 +16,7 @@ namespace net {
 class ClientSocketPoolManager;
 class HttpNetworkSession;
 class HttpStreamFactory;
+class NetworkStreamThrottler;
 class ProxyService;
 
 class NET_EXPORT_PRIVATE HttpNetworkSessionPeer {
@@ -34,6 +35,9 @@ class NET_EXPORT_PRIVATE HttpNetworkSessionPeer {
   void SetHttpStreamFactoryForWebSocket(
       std::unique_ptr<HttpStreamFactory> http_stream_factory_for_websocket);
 
+  void SetNetworkStreamThrottler(
+      std::unique_ptr<NetworkStreamThrottler> network_stream_throttler);
+
  private:
   HttpNetworkSession* const session_;