Add tracing to prefs for analyzing startup performance

chrome/browser/prefs/browser_prefs.cc

 // Copyright 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/prefs/browser_prefs.h"
 
 #include "apps/prefs.h"
+#include "base/debug/trace_event.h"
 #include "base/prefs/pref_registry_simple.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/about_flags.h"
 #include "chrome/browser/accessibility/invert_bubble_prefs.h"
 #include "chrome/browser/background/background_mode_manager.h"
 #include "chrome/browser/bookmarks/bookmark_prompt_prefs.h"
 #include "chrome/browser/bookmarks/bookmark_utils.h"
 #include "chrome/browser/browser_process_impl.h"
 #include "chrome/browser/browser_shutdown.h"
 #include "chrome/browser/chrome_content_browser_client.h"
@@ skipping 254 matching lines @@
   policy::AutoEnrollmentClient::RegisterPrefs(registry);
   policy::DeviceStatusCollector::RegisterPrefs(registry);
 #endif
 
 #if defined(OS_MACOSX)
   confirm_quit::RegisterLocalState(registry);
 #endif
 }
 
 void RegisterUserPrefs(user_prefs::PrefRegistrySyncable* registry) {
+  TRACE_EVENT0("browser", "chrome::RegisterUserPrefs")

[battre, 2013/06/03 20:24:21]

nit: all TRACE_EVENT0 usage that I found in code search and also the examples
put a trailing ; the end of the statement.

   // User prefs. Please keep this list alphabetized.
   AlternateErrorPageTabObserver::RegisterUserPrefs(registry);
   autofill::AutofillDialogControllerImpl::RegisterUserPrefs(registry);
   autofill::AutofillManager::RegisterUserPrefs(registry);
   BookmarkPromptPrefs::RegisterUserPrefs(registry);
   bookmark_utils::RegisterUserPrefs(registry);
   browser_sync::SyncPrefs::RegisterUserPrefs(registry);
   chrome::RegisterInstantUserPrefs(registry);
   ChromeContentBrowserClient::RegisterUserPrefs(registry);
   ChromeDownloadManagerDelegate::RegisterUserPrefs(registry);
@@ skipping 171 matching lines @@
     }
     local_state->ClearPref(prefs::kLastPromptedGoogleURL);
 
     current_version |= GOOGLE_URL_TRACKER_PREFS;
     local_state->SetInteger(prefs::kMultipleProfilePrefMigration,
                             current_version);
   }
 }
 
 }  // namespace chrome