Add histograms to NetworkChangeNotifier to identify ways to improve interface

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 377 matching lines @@
 
   DCHECK(!globals_);
   globals_ = new Globals;
 
   // Add an observer that will emit network change events to the ChromeNetLog.
   // Assuming NetworkChangeNotifier dispatches in FIFO order, we should be
   // logging the network change before other IO thread consumers respond to it.
   network_change_observer_.reset(
       new LoggingNetworkChangeObserver(net_log_));
 
+  // Setup the HistogramWatcher to run on the IO thread.
+  net::NetworkChangeNotifier::InitHistogramWatcher();
+
   globals_->extension_event_router_forwarder =
       extension_event_router_forwarder_;
   ChromeNetworkDelegate* network_delegate = new ChromeNetworkDelegate(
       extension_event_router_forwarder_,
       NULL,
       NULL,
       NULL,
       NULL,
       &system_enable_referrers_,
       NULL);
@@ skipping 219 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.reset(
       ConstructSystemRequestContext(globals_, net_log_));
 
   sdch_manager_->set_sdch_fetcher(
       new SdchDictionaryFetcher(system_url_request_context_getter_.get()));
 }