HPACK optimal Huffman code instrumentation and UMA collection.

net/http/http_network_session.h

Index: net/http/http_network_session.h
diff --git a/net/http/http_network_session.h b/net/http/http_network_session.h
index ac014874f1dcc066e312b24a792cee340ec7d432..fd34dadc943d4fac5657b940e33a572d17bddd2f 100644
--- a/net/http/http_network_session.h
+++ b/net/http/http_network_session.h
@@ -31,6 +31,7 @@ class CertVerifier;
 class ClientSocketFactory;
 class ClientSocketPoolManager;
 class HostResolver;
+class HpackHuffmanAggregator;
 class HttpAuthHandlerFactory;
 class HttpNetworkSessionPeer;
 class HttpProxyClientSocketPool;
@@ -152,6 +153,9 @@ class NET_EXPORT HttpNetworkSession
   NetLog* net_log() {
     return net_log_;
   }
+  HpackHuffmanAggregator* huffman_aggregator() {
+    return huffman_aggregator_.get();
+  }
 
   // Creates a Value summary of the state of the socket pools. The caller is
   // responsible for deleting the returned value.
@@ -206,6 +210,9 @@ class NET_EXPORT HttpNetworkSession
   scoped_ptr<HttpStreamFactory> http_stream_factory_for_websocket_;
   std::set<HttpResponseBodyDrainer*> response_drainers_;
 
+  // TODO(jgraettinger): Remove when Huffman collection is complete.
+  scoped_ptr<HpackHuffmanAggregator> huffman_aggregator_;
+
   Params params_;
 };