Add new histograms to measure time in PreMainMessageLoop.

chrome/browser/browser_process_impl.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/browser_process_impl.h"
 
 #include <algorithm>
 #include <map>
 #include <vector>
 
 #include "base/atomic_ref_count.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/alias.h"
 #include "base/debug/leak_annotations.h"
 #include "base/files/file_path.h"
 #include "base/metrics/field_trial.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/path_service.h"
 #include "base/prefs/json_pref_store.h"
 #include "base/prefs/pref_registry_simple.h"
 #include "base/prefs/pref_service.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/time/default_tick_clock.h"
+#include "base/trace_event/trace_event.h"
 #include "chrome/browser/chrome_browser_main.h"
 #include "chrome/browser/chrome_content_browser_client.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/component_updater/chrome_component_updater_configurator.h"
 #include "chrome/browser/component_updater/supervised_user_whitelist_installer.h"
 #include "chrome/browser/defaults.h"
 #include "chrome/browser/devtools/remote_debugging_server.h"
 #include "chrome/browser/download/download_request_limiter.h"
 #include "chrome/browser/download/download_status_updater.h"
 #include "chrome/browser/first_run/upgrade_util.h"
@@ skipping 952 matching lines @@
                    net::HttpNetworkSession::NORMAL_SOCKET_POOL)));
 }
 
 void BrowserProcessImpl::PreCreateThreads() {
   io_thread_.reset(
       new IOThread(local_state(), policy_service(), net_log_.get(),
                    extension_event_router_forwarder()));
 }
 
 void BrowserProcessImpl::PreMainMessageLoopRun() {
+  TRACE_EVENT0("startup", "BrowserProcessImpl::PreMainMessageLoopRun");
+  SCOPED_UMA_HISTOGRAM_TIMER(
+      "Startup.BrowserProcessImpl_PreMainMessageLoopRunTime");
+
 #if defined(ENABLE_CONFIGURATION_POLICY)
   // browser_policy_connector() is created very early because local_state()
   // needs policy to be initialized with the managed preference values.
   // However, policy fetches from the network and loading of disk caches
   // requires that threads are running; this Init() call lets the connector
   // resume its initialization now that the loops are spinning and the
   // system request context is available for the fetchers.
   browser_policy_connector()->Init(local_state(), system_request_context());
 #endif
 
@@ skipping 205 matching lines @@
 }
 
 void BrowserProcessImpl::OnAutoupdateTimer() {
   if (CanAutorestartForUpdate()) {
     DLOG(WARNING) << "Detected update.  Restarting browser.";
     RestartBackgroundInstance();
   }
 }
 
 #endif  // (defined(OS_WIN) || defined(OS_LINUX)) && !defined(OS_CHROMEOS)