Transmit a X-Chrome-UMA-Enabled bit to Google domains from clients that have UMA enabled.

chrome/browser/io_thread.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/io_thread.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 367 matching lines @@
       new LoggingNetworkChangeObserver(net_log_));
 
   globals_->extension_event_router_forwarder =
       extension_event_router_forwarder_;
   globals_->system_network_delegate.reset(new ChromeNetworkDelegate(
       extension_event_router_forwarder_,
       NULL,
       NULL,
       NULL,
       NULL,
+      false,
       &system_enable_referrers_));
   globals_->host_resolver.reset(
       CreateGlobalHostResolver(net_log_));
   globals_->cert_verifier.reset(net::CertVerifier::CreateDefault());
   globals_->transport_security_state.reset(new net::TransportSecurityState(""));
   globals_->ssl_config_service = GetSSLConfigService();
   globals_->http_auth_handler_factory.reset(CreateDefaultAuthHandlerFactory(
       globals_->host_resolver.get()));
   globals_->http_server_properties.reset(new net::HttpServerPropertiesImpl);
   // For the ProxyScriptFetcher, we use a direct ProxyService.
@@ skipping 201 matching lines @@
       new net::HttpNetworkLayer(
           new net::HttpNetworkSession(system_params)));
   globals_->system_ftp_transaction_factory.reset(
       new net::FtpNetworkLayer(globals_->host_resolver.get()));
   globals_->system_request_context =
       ConstructSystemRequestContext(globals_, net_log_);
 
   sdch_manager_->set_sdch_fetcher(
       new SdchDictionaryFetcher(system_url_request_context_getter_.get()));
 }