// Copyright (c) 2010 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_main.h"

#include <algorithm>
#include <string>
#include <vector>

#include "app/hi_res_timer_manager.h"
#include "app/l10n_util.h"
#include "app/resource_bundle.h"
#include "app/system_monitor.h"
#include "base/command_line.h"
#include "base/field_trial.h"
#include "base/file_util.h"
#include "base/histogram.h"
#include "base/scoped_nsautorelease_pool.h"
#include "base/path_service.h"
#include "base/platform_thread.h"
#include "base/process_util.h"
#include "base/string_piece.h"
#include "base/string_util.h"
#include "base/sys_string_conversions.h"
#include "base/time.h"
#include "base/tracked_objects.h"
#include "base/values.h"
#include "build/build_config.h"
#include "chrome/browser/browser_main_win.h"
#include "chrome/browser/browser_init.h"
#include "chrome/browser/browser_list.h"
#include "chrome/browser/browser_prefs.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/browser_process_impl.h"
#include "chrome/browser/browser_shutdown.h"
#include "chrome/browser/chrome_thread.h"
#include "chrome/browser/dom_ui/chrome_url_data_manager.h"
#include "chrome/browser/extensions/extension_protocols.h"
#include "chrome/browser/extensions/extensions_service.h"
#include "chrome/browser/first_run.h"
#include "chrome/browser/jankometer.h"
#include "chrome/browser/metrics/histogram_synchronizer.h"
#include "chrome/browser/metrics/metrics_service.h"
#include "chrome/browser/net/predictor_api.h"
#include "chrome/browser/net/metadata_url_request.h"
#include "chrome/browser/net/sdch_dictionary_fetcher.h"
#include "chrome/browser/net/websocket_experiment/websocket_experiment_runner.h"
#include "chrome/browser/plugin_service.h"
#include "chrome/browser/pref_service.h"
#include "chrome/browser/pref_value_store.h"
#include "chrome/browser/process_singleton.h"
#include "chrome/browser/profile.h"
#include "chrome/browser/profile_manager.h"
#include "chrome/browser/renderer_host/resource_dispatcher_host.h"
#include "chrome/browser/search_engines/template_url_model.h"
#include "chrome/browser/search_engines/template_url_prepopulate_data.h"
#include "chrome/browser/shell_integration.h"
#include "chrome/browser/translate/translate_manager2.h"
#include "chrome/common/child_process.h"
#include "chrome/common/chrome_constants.h"
#include "chrome/common/chrome_paths.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/json_pref_store.h"
#include "chrome/common/jstemplate_builder.h"
#include "chrome/common/main_function_params.h"
#include "chrome/common/net/net_resource_provider.h"
#include "chrome/common/pref_names.h"
#include "chrome/common/result_codes.h"
#include "chrome/installer/util/google_update_settings.h"
#include "chrome/installer/util/master_preferences.h"
#include "grit/app_locale_settings.h"
#include "grit/chromium_strings.h"
#include "grit/generated_resources.h"
#include "net/base/cookie_monster.h"
#include "net/base/net_module.h"
#include "net/base/network_change_notifier.h"
#include "net/http/http_network_layer.h"
#include "net/http/http_network_session.h"
#include "net/http/http_network_transaction.h"
#include "net/socket/client_socket_pool_base.h"
#include "net/spdy/spdy_session_pool.h"

#if defined(OS_POSIX)
// TODO(port): get rid of this include. It's used just to provide declarations
// and stub definitions for classes we encouter during the porting effort.
#include <errno.h>
#include <signal.h>
#include <sys/resource.h>
#include "base/eintr_wrapper.h"
#endif

#if defined(USE_LINUX_BREAKPAD)
#include "base/linux_util.h"
#include "chrome/app/breakpad_linux.h"
#endif

#if defined(OS_POSIX) && !defined(OS_MACOSX)
#include "chrome/browser/gtk/gtk_util.h"
#endif

#if defined(OS_CHROMEOS)
#include "chrome/browser/chromeos/boot_times_loader.h"
#endif

// TODO(port): several win-only methods have been pulled out of this, but
// BrowserMain() as a whole needs to be broken apart so that it's usable by
// other platforms. For now, it's just a stub. This is a serious work in
// progress and should not be taken as an indication of a real refactoring.

#if defined(OS_WIN)
#include <windows.h>
#include <commctrl.h>
#include <shellapi.h>

#include "app/l10n_util_win.h"
#include "app/win_util.h"
#include "base/registry.h"
#include "base/win_util.h"
#include "chrome/browser/browser.h"
#include "chrome/browser/browser_trial.h"
#include "chrome/browser/metrics/user_metrics.h"
#include "chrome/browser/net/url_fixer_upper.h"
#include "chrome/browser/rlz/rlz.h"
#include "chrome/browser/views/user_data_dir_dialog.h"
#include "chrome/common/env_vars.h"
#include "chrome/common/sandbox_policy.h"
#include "chrome/installer/util/browser_distribution.h"
#include "chrome/installer/util/google_chrome_sxs_distribution.h"
#include "chrome/installer/util/helper.h"
#include "chrome/installer/util/install_util.h"
#include "chrome/installer/util/shell_util.h"
#include "chrome/installer/util/version.h"
#include "net/base/net_util.h"
#include "net/base/sdch_manager.h"
#include "net/base/winsock_init.h"
#include "net/socket/ssl_client_socket_nss_factory.h"
#include "printing/printed_document.h"
#include "sandbox/src/sandbox.h"
#endif  // defined(OS_WIN)

#if defined(OS_MACOSX)
#include <Security/Security.h>
#include "chrome/browser/cocoa/install_from_dmg.h"
#include "net/socket/ssl_client_socket_mac_factory.h"
#endif

#if defined(OS_MACOSX) || defined(OS_WIN)
#include "base/nss_util.h"
#endif

#if defined(TOOLKIT_VIEWS)
#include "chrome/browser/views/chrome_views_delegate.h"
#include "views/focus/accelerator_handler.h"
#endif

#if defined(OS_CHROMEOS)
#include "chrome/browser/chromeos/cros/cros_library.h"
#include "chrome/browser/chromeos/cros/screen_lock_library.h"
#include "chrome/browser/chromeos/customization_document.h"
#include "chrome/browser/chromeos/external_metrics.h"
#include "chrome/browser/chromeos/login/screen_locker.h"
#include "chrome/browser/chromeos/login/user_manager.h"
#include "chrome/browser/views/browser_dialogs.h"
#endif

namespace {

// This function provides some ways to test crash and assertion handling
// behavior of the program.
void HandleTestParameters(const CommandLine& command_line) {
  // This parameter causes an assertion.
  if (command_line.HasSwitch(switches::kBrowserAssertTest)) {
    DCHECK(false);
  }

  // This parameter causes a null pointer crash (crash reporter trigger).
  if (command_line.HasSwitch(switches::kBrowserCrashTest)) {
    int* bad_pointer = NULL;
    *bad_pointer = 0;
  }

#if defined(OS_CHROMEOS)
  // Test loading libcros and exit. We return 0 if the library could be loaded,
  // and 1 if it can't be. This is for validation that the library is installed
  // and versioned properly for Chrome to find.
  if (command_line.HasSwitch(switches::kTestLoadLibcros))
    exit(!chromeos::CrosLibrary::Get()->EnsureLoaded());
#endif
}

void RunUIMessageLoop(BrowserProcess* browser_process) {
#if defined(TOOLKIT_VIEWS)
  views::AcceleratorHandler accelerator_handler;
  MessageLoopForUI::current()->Run(&accelerator_handler);
#elif defined(USE_X11)
  MessageLoopForUI::current()->Run(NULL);
#elif defined(OS_POSIX)
  MessageLoopForUI::current()->Run();
#endif
}

#if defined(OS_POSIX)
// See comment in BrowserMain, where sigaction is called.
void SIGCHLDHandler(int signal) {
}

int g_shutdown_pipe_write_fd = -1;
int g_shutdown_pipe_read_fd = -1;

// Common code between SIG{HUP, INT, TERM}Handler.
void GracefulShutdownHandler(int signal) {
  // Reinstall the default handler.  We had one shot at graceful shutdown.
  struct sigaction action;
  memset(&action, 0, sizeof(action));
  action.sa_handler = SIG_DFL;
  RAW_CHECK(sigaction(signal, &action, NULL) == 0);

  RAW_CHECK(g_shutdown_pipe_write_fd != -1);
  RAW_CHECK(g_shutdown_pipe_read_fd != -1);
  size_t bytes_written = 0;
  do {
    int rv = HANDLE_EINTR(
        write(g_shutdown_pipe_write_fd,
              reinterpret_cast<const char*>(&signal) + bytes_written,
              sizeof(signal) - bytes_written));
    RAW_CHECK(rv >= 0);
    bytes_written += rv;
  } while (bytes_written < sizeof(signal));

  RAW_LOG(INFO,
          "Successfully wrote to shutdown pipe, resetting signal handler.");
}

// See comment in BrowserMain, where sigaction is called.
void SIGHUPHandler(int signal) {
  RAW_CHECK(signal == SIGHUP);
  RAW_LOG(INFO, "Handling SIGHUP.");
  GracefulShutdownHandler(signal);
}

// See comment in BrowserMain, where sigaction is called.
void SIGINTHandler(int signal) {
  RAW_CHECK(signal == SIGINT);
  RAW_LOG(INFO, "Handling SIGINT.");
  GracefulShutdownHandler(signal);
}

// See comment in BrowserMain, where sigaction is called.
void SIGTERMHandler(int signal) {
  RAW_CHECK(signal == SIGTERM);
  RAW_LOG(INFO, "Handling SIGTERM.");
  GracefulShutdownHandler(signal);
}

class ShutdownDetector : public PlatformThread::Delegate {
 public:
  explicit ShutdownDetector(int shutdown_fd);

  virtual void ThreadMain();

 private:
  const int shutdown_fd_;

  DISALLOW_COPY_AND_ASSIGN(ShutdownDetector);
};

ShutdownDetector::ShutdownDetector(int shutdown_fd)
    : shutdown_fd_(shutdown_fd) {
  CHECK_NE(shutdown_fd_, -1);
}

void ShutdownDetector::ThreadMain() {
  int signal;
  size_t bytes_read = 0;
  ssize_t ret;
  do {
    ret = HANDLE_EINTR(
        read(shutdown_fd_,
             reinterpret_cast<char*>(&signal) + bytes_read,
             sizeof(signal) - bytes_read));
    if (ret < 0) {
      NOTREACHED() << "Unexpected error: " << strerror(errno);
      break;
    } else if (ret == 0) {
      NOTREACHED() << "Unexpected closure of shutdown pipe.";
      break;
    }
    bytes_read += ret;
  } while (bytes_read < sizeof(signal));

  LOG(INFO) << "Handling shutdown for signal " << signal << ".";

  if (!ChromeThread::PostTask(
      ChromeThread::UI, FROM_HERE,
      NewRunnableFunction(BrowserList::CloseAllBrowsersAndExit))) {
    // Without a UI thread to post the exit task to, there aren't many
    // options.  Raise the signal again.  The default handler will pick it up
    // and cause an ungraceful exit.
    RAW_LOG(WARNING, "No UI thread, exiting ungracefully.");
    kill(getpid(), signal);

    // The signal may be handled on another thread.  Give that a chance to
    // happen.
    sleep(3);

    // We really should be dead by now.  For whatever reason, we're not. Exit
    // immediately, with the exit status set to the signal number with bit 8
    // set.  On the systems that we care about, this exit status is what is
    // normally used to indicate an exit by this signal's default handler.
    // This mechanism isn't a de jure standard, but even in the worst case, it
    // should at least result in an immediate exit.
    RAW_LOG(WARNING, "Still here, exiting really ungracefully.");
    _exit(signal | (1 << 7));
  }
}

// Sets the file descriptor soft limit to |max_descriptors| or the OS hard
// limit, whichever is lower.
void SetFileDescriptorLimit(unsigned int max_descriptors) {
  struct rlimit limits;
  if (getrlimit(RLIMIT_NOFILE, &limits) == 0) {
    unsigned int new_limit = max_descriptors;
    if (limits.rlim_max > 0 && limits.rlim_max < max_descriptors) {
      new_limit = limits.rlim_max;
    }
    limits.rlim_cur = new_limit;
    if (setrlimit(RLIMIT_NOFILE, &limits) != 0) {
      PLOG(INFO) << "Failed to set file descriptor limit";
    }
  } else {
    PLOG(INFO) << "Failed to get file descriptor limit";
  }
}
#endif

void AddFirstRunNewTabs(BrowserInit* browser_init,
                        const std::vector<GURL>& new_tabs) {
  for (std::vector<GURL>::const_iterator it = new_tabs.begin();
       it != new_tabs.end(); ++it) {
    if (it->is_valid())
      browser_init->AddFirstRunTab(*it);
  }
}

#if defined(USE_LINUX_BREAKPAD)
class GetLinuxDistroTask : public Task {
 public:
  explicit GetLinuxDistroTask() {}

  virtual void Run() {
    base::GetLinuxDistro();  // Initialize base::linux_distro if needed.
  }

  DISALLOW_COPY_AND_ASSIGN(GetLinuxDistroTask);
};
#endif  // USE_LINUX_BREAKPAD

void InitializeNetworkOptions(const CommandLine& parsed_command_line) {
  if (parsed_command_line.HasSwitch(switches::kEnableFileCookies)) {
    // Enable cookie storage for file:// URLs.  Must do this before the first
    // Profile (and therefore the first CookieMonster) is created.
    net::CookieMonster::EnableFileScheme();
  }

  if (parsed_command_line.HasSwitch(switches::kFixedHttpPort)) {
    net::HttpNetworkSession::set_fixed_http_port(StringToInt(
        parsed_command_line.GetSwitchValueASCII(switches::kFixedHttpPort)));
  }

  if (parsed_command_line.HasSwitch(switches::kFixedHttpsPort)) {
    net::HttpNetworkSession::set_fixed_https_port(StringToInt(
        parsed_command_line.GetSwitchValueASCII(switches::kFixedHttpsPort)));
  }

  if (parsed_command_line.HasSwitch(switches::kIgnoreCertificateErrors))
    net::HttpNetworkTransaction::IgnoreCertificateErrors(true);

  if (parsed_command_line.HasSwitch(switches::kHostRules))
    net::HttpNetworkTransaction::SetHostMappingRules(
        parsed_command_line.GetSwitchValueASCII(switches::kHostRules));

  if (parsed_command_line.HasSwitch(switches::kMaxSpdySessionsPerDomain)) {
    int value = StringToInt(
        parsed_command_line.GetSwitchValueASCII(
            switches::kMaxSpdySessionsPerDomain));
    net::SpdySessionPool::set_max_sessions_per_domain(value);
  }
}

// Creates key child threads. We need to do this explicitly since
// ChromeThread::PostTask silently deletes a posted task if the target message
// loop isn't created.
void CreateChildThreads(BrowserProcessImpl* process) {
  process->db_thread();
  process->file_thread();
  process->process_launcher_thread();
  process->cache_thread();
  process->io_thread();
}

// Returns the new local state object, guaranteed non-NULL.
PrefService* InitializeLocalState(const CommandLine& parsed_command_line,
                                  bool is_first_run) {
  FilePath local_state_path;
  PathService::Get(chrome::FILE_LOCAL_STATE, &local_state_path);
  bool local_state_file_exists = file_util::PathExists(local_state_path);

  // Load local state.  This includes the application locale so we know which
  // locale dll to load.
  PrefService* local_state = g_browser_process->local_state();
  DCHECK(local_state);

  // Initialize ResourceBundle which handles files loaded from external
  // sources. This has to be done before uninstall code path and before prefs
  // are registered.
  local_state->RegisterStringPref(prefs::kApplicationLocale, "");
  local_state->RegisterBooleanPref(prefs::kMetricsReportingEnabled,
      GoogleUpdateSettings::GetCollectStatsConsent());

  if (is_first_run) {
#if defined(OS_WIN)
    // During first run we read the google_update registry key to find what
    // language the user selected when downloading the installer. This
    // becomes our default language in the prefs.
    // Other platforms obey the system locale.
    std::wstring install_lang;
    if (GoogleUpdateSettings::GetLanguage(&install_lang)) {
      local_state->SetString(prefs::kApplicationLocale,
                             WideToASCII(install_lang));
    }
#endif  // defined(OS_WIN)
  }

  // If the local state file for the current profile doesn't exist and the
  // parent profile command line flag is present, then we should inherit some
  // local state from the parent profile.
  // Checking that the local state file for the current profile doesn't exist
  // is the most robust way to determine whether we need to inherit or not
  // since the parent profile command line flag can be present even when the
  // current profile is not a new one, and in that case we do not want to
  // inherit and reset the user's setting.
  if (!local_state_file_exists &&
      parsed_command_line.HasSwitch(switches::kParentProfile)) {
    FilePath parent_profile =
        parsed_command_line.GetSwitchValuePath(switches::kParentProfile);
    scoped_ptr<PrefService> parent_local_state(
        PrefService::CreatePrefService(parent_profile));
    parent_local_state->RegisterStringPref(prefs::kApplicationLocale,
                                           std::string());
    // Right now, we only inherit the locale setting from the parent profile.
    local_state->SetString(
        prefs::kApplicationLocale,
        parent_local_state->GetString(prefs::kApplicationLocale));
  }

  return local_state;
}

// Windows-specific initialization code for the sandbox broker services. This
// is just a NOP on non-Windows platforms to reduce ifdefs later on.
void InitializeBrokerServices(const MainFunctionParams& parameters,
                              const CommandLine& parsed_command_line) {
#if defined(OS_WIN)
  sandbox::BrokerServices* broker_services =
      parameters.sandbox_info_.BrokerServices();
  if (broker_services) {
    sandbox::InitBrokerServices(broker_services);
    if (!parsed_command_line.HasSwitch(switches::kNoSandbox)) {
      bool use_winsta = !parsed_command_line.HasSwitch(
                            switches::kDisableAltWinstation);
      // Precreate the desktop and window station used by the renderers.
      sandbox::TargetPolicy* policy = broker_services->CreatePolicy();
      sandbox::ResultCode result = policy->CreateAlternateDesktop(use_winsta);
      CHECK(sandbox::SBOX_ERROR_FAILED_TO_SWITCH_BACK_WINSTATION != result);
      policy->Release();
    }
  }
#endif
}

// Initializes the metrics service with the configuration for this process,
// returning the created service (guaranteed non-NULL).
MetricsService* InitializeMetrics(const CommandLine& parsed_command_line,
                                  const PrefService* local_state) {
#if defined(OS_WIN)
  if (InstallUtil::IsChromeFrameProcess())
    MetricsLog::set_version_extension("-F");
#elif defined(ARCH_CPU_64_BITS)
  MetricsLog::set_version_extension("-64");
#endif  // defined(OS_WIN)

  MetricsService* metrics = g_browser_process->metrics_service();

  if (parsed_command_line.HasSwitch(switches::kMetricsRecordingOnly)) {
    // If we're testing then we don't care what the user preference is, we turn
    // on recording, but not reporting, otherwise tests fail.
    metrics->StartRecordingOnly();
  } else {
    // If the user permits metrics reporting with the checkbox in the
    // prefs, we turn on recording.  We disable metrics completely for
    // non-official builds.
#if defined(GOOGLE_CHROME_BUILD)
    bool enabled = local_state->GetBoolean(prefs::kMetricsReportingEnabled);
    metrics->SetUserPermitsUpload(enabled);
    if (enabled) {
      metrics->Start();
      chrome_browser_net_websocket_experiment::
          WebSocketExperimentRunner::Start();
    }
#endif
  }

  return metrics;
}

// Initializes the profile, possibly doing some user prompting to pick a
// fallback profile. Returns the newly created profile, or NULL if startup
// should not continue.
Profile* CreateProfile(const MainFunctionParams& parameters,
                       const FilePath& user_data_dir) {
  Profile* profile = g_browser_process->profile_manager()->GetDefaultProfile(
      user_data_dir);
  if (profile)
    return profile;

#if defined(OS_WIN)
  // Ideally, we should be able to run w/o access to disk.  For now, we
  // prompt the user to pick a different user-data-dir and restart chrome
  // with the new dir.
  // http://code.google.com/p/chromium/issues/detail?id=11510
  FilePath new_user_data_dir = UserDataDirDialog::RunUserDataDirDialog(
      user_data_dir);
  if (!parameters.ui_task && browser_shutdown::delete_resources_on_shutdown) {
    // Only delete the resources if we're not running tests. If we're running
    // tests the resources need to be reused as many places in the UI cache
    // SkBitmaps from the ResourceBundle.
    ResourceBundle::CleanupSharedInstance();
  }

  if (!new_user_data_dir.empty()) {
    // Because of the way CommandLine parses, it's sufficient to append a new
    // --user-data-dir switch.  The last flag of the same name wins.
    // TODO(tc): It would be nice to remove the flag we don't want, but that
    // sounds risky if we parse differently than CommandLineToArgvW.
    CommandLine new_command_line = parameters.command_line_;
    new_command_line.AppendSwitchWithValue(switches::kUserDataDir,
                                           new_user_data_dir.ToWStringHack());
    base::LaunchApp(new_command_line, false, false, NULL);
  }
#else
  // TODO(port): fix this.  See comments near the definition of
  // user_data_dir.  It is better to CHECK-fail here than it is to
  // silently exit because of missing code in the above test.
  CHECK(profile) << "Cannot get default profile.";
#endif

  return NULL;
}

#if defined(OS_WIN)

// gfx::Font callbacks
void AdjustUIFont(LOGFONT* logfont) {
  l10n_util::AdjustUIFont(logfont);
}

int GetMinimumFontSize() {
  return StringToInt(l10n_util::GetString(IDS_MINIMUM_UI_FONT_SIZE).c_str());
}

#endif

#if defined(TOOLKIT_GTK)
void InitializeToolkit() {
  // It is important for this to happen before the first run dialog, as it
  // styles the dialog as well.
  gtk_util::InitRCStyles();
}
#elif defined(TOOLKIT_VIEWS)
void InitializeToolkit() {
  // The delegate needs to be set before any UI is created so that windows
  // display the correct icon.
  if (!views::ViewsDelegate::views_delegate)
    views::ViewsDelegate::views_delegate = new ChromeViewsDelegate;

#if defined(OS_WIN)
  gfx::Font::adjust_font_callback = &AdjustUIFont;
  gfx::Font::get_minimum_font_size_callback = &GetMinimumFontSize;

  // Init common control sex.
  INITCOMMONCONTROLSEX config;
  config.dwSize = sizeof(config);
  config.dwICC = ICC_WIN95_CLASSES;
  InitCommonControlsEx(&config);
#endif
}
#else
void InitializeToolkit() {
}
#endif

#if defined(OS_CHROMEOS)

void OptionallyRunChromeOSLoginManager(const CommandLine& parsed_command_line) {
  if (parsed_command_line.HasSwitch(switches::kLoginManager)) {
    std::string first_screen =
        parsed_command_line.GetSwitchValueASCII(switches::kLoginScreen);
    std::string size_arg =
        parsed_command_line.GetSwitchValueASCII(
            switches::kLoginScreenSize);
    gfx::Size size(0, 0);
    // Allow the size of the login window to be set explicitly. If not set,
    // default to the entire screen. This is mostly useful for testing.
    if (size_arg.size()) {
      std::vector<std::string> dimensions;
      SplitString(size_arg, ',', &dimensions);
      if (dimensions.size() == 2)
        size.SetSize(StringToInt(dimensions[0]), StringToInt(dimensions[1]));
    }
    browser::ShowLoginWizard(first_screen, size);
  }
}

bool OptionallyApplyServicesCustomizationFromCommandLine(
    const CommandLine& parsed_command_line,
    BrowserInit* browser_init) {
  // For Chrome OS, we may need to fetch OEM partner's services customization
  // manifest and apply the customizations. This happens on the very first run
  // or if startup manifest is passed on the command line.
  scoped_ptr<chromeos::ServicesCustomizationDocument> customization;
  customization.reset(new chromeos::ServicesCustomizationDocument());
  bool manifest_loaded = false;
  if (parsed_command_line.HasSwitch(switches::kServicesManifest)) {
    // Load manifest from file specified by command line switch.
    FilePath manifest_path =
        parsed_command_line.GetSwitchValuePath(switches::kServicesManifest);
    manifest_loaded = customization->LoadManifestFromFile(manifest_path);
    DCHECK(manifest_loaded) << manifest_path.value();
  }
  // If manifest was loaded successfully, apply the customizations.
  if (manifest_loaded) {
    browser_init->ApplyServicesCustomization(customization.get());
  }
  return manifest_loaded;
}

#else

void OptionallyRunChromeOSLoginManager(const CommandLine& parsed_command_line) {
  // Dummy empty function for non-ChromeOS builds to avoid extra ifdefs below.
}

bool OptionallyApplyServicesCustomizationFromCommandLine(
    const CommandLine& parsed_command_line,
    BrowserInit* browser_init) {
  // Dummy empty function for non-ChromeOS builds to avoid extra ifdefs below.
  return false;
}

#endif  // defined(OS_CHROMEOS)

#if defined(OS_MACOSX)
OSStatus KeychainCallback(SecKeychainEvent keychain_event,
                          SecKeychainCallbackInfo *info, void *context) {
  return noErr;
}
#endif

}  // namespace

#if defined(OS_WIN)
#define DLLEXPORT __declspec(dllexport)

// We use extern C for the prototype DLLEXPORT to avoid C++ name mangling.
extern "C" {
DLLEXPORT void __cdecl RelaunchChromeBrowserWithNewCommandLineIfNeeded();
}

DLLEXPORT void __cdecl RelaunchChromeBrowserWithNewCommandLineIfNeeded() {
  Upgrade::RelaunchChromeBrowserWithNewCommandLineIfNeeded();
}
#endif

// Main routine for running as the Browser process.
int BrowserMain(const MainFunctionParams& parameters) {
  const CommandLine& parsed_command_line = parameters.command_line_;
  base::ScopedNSAutoreleasePool* pool = parameters.autorelease_pool_;

  // WARNING: If we get a WM_ENDSESSION objects created on the stack here
  // are NOT deleted. If you need something to run during WM_ENDSESSION add it
  // to browser_shutdown::Shutdown or BrowserProcess::EndSession.

  // TODO(beng, brettw): someday, break this out into sub functions with well
  //                     defined roles (e.g. pre/post-profile startup, etc).

#ifdef TRACK_ALL_TASK_OBJECTS
  // Start tracking the creation and deletion of Task instance.
  // This construction MUST be done before main_message_loop, so that it is
  // destroyed after the main_message_loop.
  tracked_objects::AutoTracking tracking_objects;
#endif

#if defined(OS_POSIX)
  // We need to accept SIGCHLD, even though our handler is a no-op because
  // otherwise we cannot wait on children. (According to POSIX 2001.)
  struct sigaction action;
  memset(&action, 0, sizeof(action));
  action.sa_handler = SIGCHLDHandler;
  CHECK(sigaction(SIGCHLD, &action, NULL) == 0);

  // If adding to this list of signal handlers, note the new signal probably
  // needs to be reset in child processes. See
  // base/process_util_posix.cc:LaunchApp

  // We need to handle SIGTERM, because that is how many POSIX-based distros ask
  // processes to quit gracefully at shutdown time.
  memset(&action, 0, sizeof(action));
  action.sa_handler = SIGTERMHandler;
  CHECK(sigaction(SIGTERM, &action, NULL) == 0);
  // Also handle SIGINT - when the user terminates the browser via Ctrl+C.
  // If the browser process is being debugged, GDB will catch the SIGINT first.
  action.sa_handler = SIGINTHandler;
  CHECK(sigaction(SIGINT, &action, NULL) == 0);
  // And SIGHUP, for when the terminal disappears. On shutdown, many Linux
  // distros send SIGHUP, SIGTERM, and then SIGKILL.
  action.sa_handler = SIGHUPHandler;
  CHECK(sigaction(SIGHUP, &action, NULL) == 0);

  const std::string fd_limit_string =
      parsed_command_line.GetSwitchValueASCII(switches::kFileDescriptorLimit);
  int fd_limit = 0;
  if (!fd_limit_string.empty()) {
    StringToInt(fd_limit_string, &fd_limit);
  }
#if defined(OS_MACOSX)
  // We use quite a few file descriptors for our IPC, and the default limit on
  // the Mac is low (256), so bump it up if there is no explicit override.
  if (fd_limit == 0) {
    fd_limit = 1024;
  }
#endif  // OS_MACOSX
  if (fd_limit > 0) {
    SetFileDescriptorLimit(fd_limit);
  }
#endif  // OS_POSIX

#if defined(OS_WIN)
  // Initialize Winsock.
  net::EnsureWinsockInit();
#endif  // defined(OS_WIN)

  // Initialize statistical testing infrastructure for entire browser.
  FieldTrialList field_trial;

  // This is an A/B test for the maximum number of persistent connections per
  // host.  Currently Chrome, Firefox, and IE8 have this value set at 6.
  // Safari uses 4, and Fasterfox (a plugin for Firefox that supposedly
  // configures it to run faster) uses 8.  We would like to see how much of an
  // effect this value has on browsing.  Too large a value might cause us to
  // run into SYN flood detection mechanisms.
  const FieldTrial::Probability kConnDivisor = 100;
  const FieldTrial::Probability kConn16 = 10;  // 10% probability
  const FieldTrial::Probability kRemainingConn = 30;  // 30% probability

  scoped_refptr<FieldTrial> conn_trial =
      new FieldTrial("ConnCountImpact", kConnDivisor);

  const int conn_16 = conn_trial->AppendGroup("_conn_count_16", kConn16);
  const int conn_4 = conn_trial->AppendGroup("_conn_count_4", kRemainingConn);
  const int conn_8 = conn_trial->AppendGroup("_conn_count_8", kRemainingConn);
  const int conn_6 = conn_trial->AppendGroup("_conn_count_6",
      FieldTrial::kAllRemainingProbability);

  const int conn_trial_grp = conn_trial->group();

  if (conn_trial_grp == conn_4) {
    net::HttpNetworkSession::set_max_sockets_per_group(4);
  } else if (conn_trial_grp == conn_6) {
    // This (6) is the current default value.
    net::HttpNetworkSession::set_max_sockets_per_group(6);
  } else if (conn_trial_grp == conn_8) {
    net::HttpNetworkSession::set_max_sockets_per_group(8);
  } else if (conn_trial_grp == conn_16) {
    net::HttpNetworkSession::set_max_sockets_per_group(16);
  } else {
    NOTREACHED();
  }

  // A/B test for determining a value for unused socket timeout.  Currently the
  // timeout defaults to 10 seconds.  Having this value set too low won't allow
  // us to take advantage of idle sockets.  Setting it to too high could
  // possibly result in more ERR_CONNECT_RESETs, requiring one RTT to receive
  // the RST packet and possibly another RTT to re-establish the connection.
  const FieldTrial::Probability kIdleSktToDivisor = 100;  // Idle socket timeout
  const FieldTrial::Probability kSktToProb = 25;  // 25% probability

  scoped_refptr<FieldTrial> socket_timeout_trial =
      new FieldTrial("IdleSktToImpact", kIdleSktToDivisor);

  const int socket_timeout_5 =
      socket_timeout_trial->AppendGroup("_idle_timeout_5", kSktToProb);
  const int socket_timeout_10 =
      socket_timeout_trial->AppendGroup("_idle_timeout_10", kSktToProb);
  const int socket_timeout_20 =
      socket_timeout_trial->AppendGroup("_idle_timeout_20", kSktToProb);
  const int socket_timeout_60 =
      socket_timeout_trial->AppendGroup("_idle_timeout_60",
                                        FieldTrial::kAllRemainingProbability);

  const int idle_to_trial_grp = socket_timeout_trial->group();

  if (idle_to_trial_grp == socket_timeout_5) {
    net::ClientSocketPool::set_unused_idle_socket_timeout(5);
  } else if (idle_to_trial_grp == socket_timeout_10) {
    // This (10 seconds) is the current default value.
    net::ClientSocketPool::set_unused_idle_socket_timeout(10);
  } else if (idle_to_trial_grp == socket_timeout_20) {
    net::ClientSocketPool::set_unused_idle_socket_timeout(20);
  } else if (idle_to_trial_grp == socket_timeout_60) {
    net::ClientSocketPool::set_unused_idle_socket_timeout(60);
  } else {
    NOTREACHED();
  }

  // When --use-spdy not set, users will be in A/B test for spdy.
  // group A (_npn_with_spdy): this means npn and spdy are enabled. In
  // case server supports spdy, browser will use spdy.
  // group B (_npn_with_http): this means npn is enabled but spdy
  // won't be used. Http is still used for all requests.
  // default group: no npn or spdy is involved. The "old" non-spdy chrome
  // behavior.
  bool is_spdy_trial = false;
  if (parsed_command_line.HasSwitch(switches::kUseSpdy)) {
    std::string spdy_mode =
        parsed_command_line.GetSwitchValueASCII(switches::kUseSpdy);
    net::HttpNetworkLayer::EnableSpdy(spdy_mode);
  } else {
    const FieldTrial::Probability kSpdyDivisor = 1000;
    // TODO(lzheng): Increase these values to enable more spdy tests.
    // To enable 100% npn_with_spdy, set npnhttp_probability = 0 and set
    // npnspdy_probability = FieldTrial::kAllRemainingProbability.
    FieldTrial::Probability npnhttp_probability = 250;  // 25%
    FieldTrial::Probability npnspdy_probability = 250;  // 25%
#if defined(OS_WIN)
    // Enable the A/B test for SxS. SxS is only available on windows
    std::wstring channel;
    if (BrowserDistribution::GetDistribution()->GetChromeChannel(&channel) &&
        channel == GoogleChromeSxSDistribution::ChannelName()) {
      npnhttp_probability = 500;
      npnspdy_probability = 500;
    }
#endif
    scoped_refptr<FieldTrial> trial =
        new FieldTrial("SpdyImpact", kSpdyDivisor);
    // npn with only http support, no spdy.
    int npn_http_grp =
        trial->AppendGroup("_npn_with_http", npnhttp_probability);
    // npn with spdy support.
    int npn_spdy_grp =
        trial->AppendGroup("_npn_with_spdy", npnspdy_probability);
    int trial_grp = trial->group();
    if (trial_grp == npn_http_grp) {
      is_spdy_trial = true;
      net::HttpNetworkLayer::EnableSpdy("npn-http");
    } else if (trial_grp == npn_spdy_grp) {
      is_spdy_trial = true;
      net::HttpNetworkLayer::EnableSpdy("npn");
    } else {
      CHECK(!is_spdy_trial);
    }
  }

  // Use NSS for SSL by default.
#if defined(OS_MACOSX)
  // The default client socket factory uses NSS for SSL by default on Mac.
  if (parsed_command_line.HasSwitch(switches::kUseSystemSSL)) {
    net::ClientSocketFactory::SetSSLClientSocketFactory(
        net::SSLClientSocketMacFactory);
  } else {
    // We want to be sure to init NSPR on the main thread.
    base::EnsureNSPRInit();
  }
#elif defined(OS_WIN)
  // Because of a build system issue (http://crbug.com/43461), the default
  // client socket factory uses SChannel (the system SSL library) for SSL by
  // default on Windows.
  if (!parsed_command_line.HasSwitch(switches::kUseSystemSSL)) {
    net::ClientSocketFactory::SetSSLClientSocketFactory(
        net::SSLClientSocketNSSFactory);
    // We want to be sure to init NSPR on the main thread.
    base::EnsureNSPRInit();
  }
#endif

  // Do platform-specific things (such as finishing initializing Cocoa)
  // prior to instantiating the message loop. This could be turned into a
  // broadcast notification.
  WillInitializeMainMessageLoop(parameters);

  MessageLoop main_message_loop(MessageLoop::TYPE_UI);

  SystemMonitor system_monitor;
  HighResolutionTimerManager hi_res_timer_manager;
  scoped_ptr<net::NetworkChangeNotifier> network_change_notifier(
      net::NetworkChangeNotifier::Create());

  const char* kThreadName = "CrBrowserMain";
  PlatformThread::SetName(kThreadName);
  main_message_loop.set_thread_name(kThreadName);

  // Register the main thread by instantiating it, but don't call any methods.
  ChromeThread main_thread(ChromeThread::UI, MessageLoop::current());
#if defined(OS_POSIX)
  int pipefd[2];
  int ret = pipe(pipefd);
  if (ret < 0) {
    PLOG(DFATAL) << "Failed to create pipe";
  } else {
    g_shutdown_pipe_read_fd = pipefd[0];
    g_shutdown_pipe_write_fd = pipefd[1];
    const size_t kShutdownDetectorThreadStackSize = 4096;
    if (!PlatformThread::CreateNonJoinable(
        kShutdownDetectorThreadStackSize,
        new ShutdownDetector(g_shutdown_pipe_read_fd))) {
      LOG(DFATAL) << "Failed to create shutdown detector task.";
    }
  }
#endif  // defined(OS_POSIX)

  FilePath user_data_dir;
#if defined(OS_WIN)
  PathService::Get(chrome::DIR_USER_DATA, &user_data_dir);
#else
  // Getting the user data dir can fail if the directory isn't
  // creatable, for example; on Windows in code below we bring up a
  // dialog prompting the user to pick a different directory.
  // However, ProcessSingleton needs a real user_data_dir on Mac/Linux,
  // so it's better to fail here than fail mysteriously elsewhere.
  CHECK(PathService::Get(chrome::DIR_USER_DATA, &user_data_dir))
      << "Must be able to get user data directory!";
#endif

  ProcessSingleton process_singleton(user_data_dir);

  bool is_first_run = FirstRun::IsChromeFirstRun() ||
      parsed_command_line.HasSwitch(switches::kFirstRun);

  scoped_ptr<BrowserProcessImpl> browser_process;
  if (parsed_command_line.HasSwitch(switches::kImport) ||
      parsed_command_line.HasSwitch(switches::kImportFromFile)) {
    // We use different BrowserProcess when importing so no GoogleURLTracker is
    // instantiated (as it makes a URLRequest and we don't have an IO thread,
    // see bug #1292702).
    browser_process.reset(new FirstRunBrowserProcess(parsed_command_line));
    is_first_run = false;
  } else {
    browser_process.reset(new BrowserProcessImpl(parsed_command_line));
  }

  // BrowserProcessImpl's constructor should set g_browser_process.
  DCHECK(g_browser_process);

#if defined(USE_LINUX_BREAKPAD)
  // Needs to be called after we have chrome::DIR_USER_DATA and
  // g_browser_process.
  g_browser_process->file_thread()->message_loop()->PostTask(FROM_HERE,
      new GetLinuxDistroTask());
  InitCrashReporter();
#endif

  // The broker service initialization needs to run early because it will
  // initialize the sandbox broker, which requires the process to swap its
  // window station. During this time all the UI will be broken. This has to
  // run before threads and windows are created.
  InitializeBrokerServices(parameters, parsed_command_line);

  PrefService* local_state = InitializeLocalState(parsed_command_line,
                                                  is_first_run);

  InitializeToolkit();  // Must happen before we try to display any UI.

  // If we're running tests (ui_task is non-null), then the ResourceBundle
  // has already been initialized.
  if (parameters.ui_task) {
    g_browser_process->SetApplicationLocale("en-US");
  } else {
    // Mac starts it earlier in WillInitializeMainMessageLoop (because
    // it is needed when loading the MainMenu.nib and the language doesn't
    // depend on anything since it comes from Cocoa.
#if defined(OS_MACOSX)
    g_browser_process->SetApplicationLocale(l10n_util::GetLocaleOverride());
#else
    std::string app_locale = ResourceBundle::InitSharedInstance(
        ASCIIToWide(local_state->GetString(prefs::kApplicationLocale)));
    g_browser_process->SetApplicationLocale(app_locale);

    FilePath resources_pack_path;
    PathService::Get(chrome::FILE_RESOURCES_PACK, &resources_pack_path);
    ResourceBundle::AddDataPackToSharedInstance(resources_pack_path);
#endif  // !defined(OS_MACOSX)
  }

#if defined(OS_POSIX) && !defined(OS_MACOSX)
  gtk_util::SetDefaultWindowIcon();
#endif

  std::string try_chrome =
      parsed_command_line.GetSwitchValueASCII(switches::kTryChromeAgain);
  if (!try_chrome.empty()) {
#if defined(OS_WIN)
    Upgrade::TryResult answer =
        Upgrade::ShowTryChromeDialog(StringToInt(try_chrome));
    if (answer == Upgrade::TD_NOT_NOW)
      return ResultCodes::NORMAL_EXIT_CANCEL;
    if (answer == Upgrade::TD_UNINSTALL_CHROME)
      return ResultCodes::NORMAL_EXIT_EXP2;
#else
    // We don't support retention experiments on Mac or Linux.
    return ResultCodes::NORMAL_EXIT;
#endif  // defined(OS_WIN)
  }

  BrowserInit browser_init;

  // On first run, we need to process the predictor preferences before the
  // browser's profile_manager object is created, but after ResourceBundle
  // is initialized.
  FirstRun::MasterPrefs master_prefs = { 0 };
  bool first_run_ui_bypass = false;  // True to skip first run UI.
  if (is_first_run) {
    first_run_ui_bypass =
        !FirstRun::ProcessMasterPreferences(user_data_dir, &master_prefs);
    AddFirstRunNewTabs(&browser_init, master_prefs.new_tabs);

    // If we are running in App mode, we do not want to show the importer
    // (first run) UI.
    if (!first_run_ui_bypass &&
        (parsed_command_line.HasSwitch(switches::kApp) ||
         parsed_command_line.HasSwitch(switches::kNoFirstRun)))
      first_run_ui_bypass = true;
  }

  if (!parsed_command_line.HasSwitch(switches::kNoErrorDialogs))
    WarnAboutMinimumSystemRequirements();

  InitializeNetworkOptions(parsed_command_line);

  // Initialize histogram statistics gathering system.
  StatisticsRecorder statistics;

  // Initialize histogram synchronizer system. This is a singleton and is used
  // for posting tasks via NewRunnableMethod. Its deleted when it goes out of
  // scope. Even though NewRunnableMethod does AddRef and Release, the object
  // will not be deleted after the Task is executed.
  scoped_refptr<HistogramSynchronizer> histogram_synchronizer =
      new HistogramSynchronizer();

  // Initialize the prefs of the local state.
  browser::RegisterLocalState(local_state);

  // Now that all preferences have been registered, set the install date
  // for the uninstall metrics if this is our first run. This only actually
  // gets used if the user has metrics reporting enabled at uninstall time.
  int64 install_date =
      local_state->GetInt64(prefs::kUninstallMetricsInstallDate);
  if (install_date == 0) {
    local_state->SetInt64(prefs::kUninstallMetricsInstallDate,
                          base::Time::Now().ToTimeT());
  }

#if defined(OS_MACOSX)
  // Get the Keychain API to register for distributed notifications on the main
  // thread, which has a proper CFRunloop, instead of later on the I/O thread,
  // which doesn't. This ensures those notifications will get delivered
  // properly. See issue 37766.
  // (Note that the callback mask here is empty. I don't want to register for
  // any callbacks, I just want to initialize the mechanism.)
  SecKeychainAddCallback(&KeychainCallback, 0, NULL);
#endif

  CreateChildThreads(browser_process.get());

#if defined(OS_CHROMEOS)
  // Now that the file thread exists we can record our stats.
  chromeos::BootTimesLoader::RecordChromeMainStats();
#endif

  // Record last shutdown time into a histogram.
  browser_shutdown::ReadLastShutdownInfo();

#if defined(OS_WIN)
  // On Windows, we use our startup as an opportunity to do upgrade/uninstall
  // tasks.  Those care whether the browser is already running.  On Linux/Mac,
  // upgrade/uninstall happen separately.
  bool already_running = Upgrade::IsBrowserAlreadyRunning();

  // If the command line specifies 'uninstall' then we need to work here
  // unless we detect another chrome browser running.
  if (parsed_command_line.HasSwitch(switches::kUninstall))
    return DoUninstallTasks(already_running);
#endif

  if (parsed_command_line.HasSwitch(switches::kHideIcons) ||
      parsed_command_line.HasSwitch(switches::kShowIcons))
    return HandleIconsCommands(parsed_command_line);
  if (parsed_command_line.HasSwitch(switches::kMakeDefaultBrowser)) {
    return ShellIntegration::SetAsDefaultBrowser() ?
        ResultCodes::NORMAL_EXIT : ResultCodes::SHELL_INTEGRATION_FAILED;
  }

#if !defined(OS_MACOSX)
  // In environments other than Mac OS X we support import of settings
  // from other browsers. In case this process is a short-lived "import"
  // process that another browser runs just to import the settings, we
  // don't want to be checking for another browser process, by design.
  if (!(parsed_command_line.HasSwitch(switches::kImport) ||
        parsed_command_line.HasSwitch(switches::kImportFromFile))) {
#endif
    // When another process is running, use that process instead of starting a
    // new one. NotifyOtherProcess will currently give the other process up to
    // 20 seconds to respond. Note that this needs to be done before we attempt
    // to read the profile.
    switch (process_singleton.NotifyOtherProcessOrCreate()) {
      case ProcessSingleton::PROCESS_NONE:
        // No process already running, fall through to starting a new one.
        break;

      case ProcessSingleton::PROCESS_NOTIFIED:
#if defined(OS_POSIX) && !defined(OS_MACOSX)
        printf("%s\n", base::SysWideToNativeMB(
                   l10n_util::GetString(IDS_USED_EXISTING_BROWSER)).c_str());
#endif
        return ResultCodes::NORMAL_EXIT;

      case ProcessSingleton::PROFILE_IN_USE:
        return ResultCodes::PROFILE_IN_USE;

      case ProcessSingleton::LOCK_ERROR:
        LOG(ERROR) << "Failed to create a ProcessSingleton for your profile "
                      "directory. This means that running multiple instances "
                      "would start multiple browser processes rather than "
                      "opening a new window in the existing process. Aborting "
                      "now to avoid profile corruption.";
        return ResultCodes::PROFILE_IN_USE;

      default:
        NOTREACHED();
    }
#if !defined(OS_MACOSX)  // closing brace for if
  }
#endif

  // Profile creation ----------------------------------------------------------

#if defined(OS_CHROMEOS)
  // Initialize the screen locker now so that it can receive
  // LOGIN_USER_CHANGED notification from UserManager.
  chromeos::ScreenLocker::InitClass();

  // This forces the ProfileManager to be created and register for the
  // notification it needs to track the logged in user.
  g_browser_process->profile_manager()->GetDefaultProfile();

  if (parsed_command_line.HasSwitch(switches::kLoginUser)) {
    std::string username =
        parsed_command_line.GetSwitchValueASCII(switches::kLoginUser);
    LOG(INFO) << "Relaunching browser for user: " << username;
    chromeos::UserManager::Get()->UserLoggedIn(username);
  }
#endif

  Profile* profile = CreateProfile(parameters, user_data_dir);
  if (!profile)
    return ResultCodes::NORMAL_EXIT;

  // Post-profile init ---------------------------------------------------------

  PrefService* user_prefs = profile->GetPrefs();
  DCHECK(user_prefs);

  // Tests should be able to tune login manager before showing it.
  // Thus only show login manager in normal (non-testing) mode.
  if (!parameters.ui_task) {
    OptionallyRunChromeOSLoginManager(parsed_command_line);
  }

#if !defined(OS_MACOSX)
  // Importing other browser settings is done in a browser-like process
  // that exits when this task has finished.
  // TODO(port):  Port to Mac
  if (parsed_command_line.HasSwitch(switches::kImport) ||
      parsed_command_line.HasSwitch(switches::kImportFromFile)) {
    return FirstRun::ImportNow(profile, parsed_command_line);
  }
#endif

#if defined(OS_WIN)
  // Do the tasks if chrome has been upgraded while it was last running.
  if (!already_running && Upgrade::DoUpgradeTasks(parsed_command_line))
    return ResultCodes::NORMAL_EXIT;
#endif

  // Check if there is any machine level Chrome installed on the current
  // machine. If yes and the current Chrome process is user level, we do not
  // allow the user level Chrome to run. So we notify the user and uninstall
  // user level Chrome.
  // Note this check should only happen here, after all the checks above
  // (uninstall, resource bundle initialization, other chrome browser
  // processes etc).
  if (CheckMachineLevelInstall())
    return ResultCodes::MACHINE_LEVEL_INSTALL_EXISTS;

  // Create the TranslateManager singleton.
  Singleton<TranslateManager2>::get();

#if defined(OS_MACOSX)
  if (!parsed_command_line.HasSwitch(switches::kNoFirstRun)) {
    // Disk image installation is sort of a first-run task, so it shares the
    // kNoFirstRun switch.
    if (MaybeInstallFromDiskImage()) {
      // The application was installed and the installed copy has been
      // launched.  This process is now obsolete.  Exit.
      return ResultCodes::NORMAL_EXIT;
    }
  }
#endif

  // Show the First Run UI if this is the first time Chrome has been run on
  // this computer, or we're being compelled to do so by a command line flag.
  // Note that this be done _after_ the PrefService is initialized and all
  // preferences are registered, since some of the code that the importer
  // touches reads preferences.
  if (is_first_run) {
    if (!first_run_ui_bypass) {
      if (!OpenFirstRunDialog(profile,
                              master_prefs.homepage_defined,
                              master_prefs.do_import_items,
                              master_prefs.dont_import_items,
                              master_prefs.run_search_engine_experiment,
                              master_prefs.randomize_search_engine_experiment,
                              &process_singleton)) {
        // The user cancelled the first run dialog box, we should exit Chrome.
        return ResultCodes::NORMAL_EXIT;
      }
#if defined(OS_POSIX)
      // On Windows, the download is tagged with enable/disable stats so there
      // is no need for this code.

      // If stats reporting was turned on by the first run dialog then toggle
      // the pref.
      if (GoogleUpdateSettings::GetCollectStatsConsent())
        local_state->SetBoolean(prefs::kMetricsReportingEnabled, true);
#endif  // OS_POSIX
    }

    Browser::SetNewHomePagePrefs(user_prefs);
  }

  // Sets things up so that if we crash from this point on, a dialog will
  // popup asking the user to restart chrome. It is done this late to avoid
  // testing against a bunch of special cases that are taken care early on.
  PrepareRestartOnCrashEnviroment(parsed_command_line);

  // Initialize and maintain network predictor module, which handles DNS
  // pre-resolution, as well as TCP/IP connection pre-warming.
  // This also registers an observer to discard data when closing incognito
  // mode.
  chrome_browser_net::PredictorInit dns_prefetch(
      user_prefs,
      local_state,
      parsed_command_line.HasSwitch(switches::kEnablePreconnect));

#if defined(OS_WIN)
  win_util::ScopedCOMInitializer com_initializer;

  // Init the RLZ library. This just binds the dll and schedules a task on the
  // file thread to be run sometime later. If this is the first run we record
  // the installation event.
  RLZTracker::InitRlzDelayed(is_first_run, master_prefs.ping_delay);
#endif

  // Configure the network module so it has access to resources.
  net::NetModule::SetResourceProvider(chrome_common_net::NetResourceProvider);

  // Register our global network handler for chrome:// and
  // chrome-extension:// URLs.
  RegisterURLRequestChromeJob();
  RegisterExtensionProtocols();
  RegisterMetadataURLRequestHandler();

  // If path to partner services customization document was passed on command
  // line, apply the customizations (Chrome OS only).
  // TODO(denisromanov): Remove this when not needed for testing.
  OptionallyApplyServicesCustomizationFromCommandLine(parsed_command_line,
                                                      &browser_init);

  // In unittest mode, this will do nothing.  In normal mode, this will create
  // the global GoogleURLTracker and IntranetRedirectDetector instances, which
  // will promptly go to sleep for five and seven seconds, respectively (to
  // avoid slowing startup), and wake up afterwards to see if they should do
  // anything else.
  //
  // A simpler way of doing all this would be to have some function which could
  // give the time elapsed since startup, and simply have these objects check
  // that when asked to initialize themselves, but this doesn't seem to exist.
  //
  // These can't be created in the BrowserProcessImpl constructor because they
  // need to read prefs that get set after that runs.
  browser_process->google_url_tracker();
  browser_process->intranet_redirect_detector();

  // Do initialize the plug-in service (and related preferences).
  PluginService::InitGlobalInstance(profile);

  // Prepare for memory caching of SDCH dictionaries.
  // Perform A/B test to measure global impact of SDCH support.
  // Set up a field trial to see what disabling SDCH does to latency of page
  // layout globally.
  FieldTrial::Probability kSDCH_DIVISOR = 1000;
  FieldTrial::Probability kSDCH_DISABLE_PROBABILITY = 1;  // 0.1% probability.
  scoped_refptr<FieldTrial> sdch_trial =
      new FieldTrial("GlobalSdch", kSDCH_DIVISOR);

  // Use default of "" so that all domains are supported.
  std::string sdch_supported_domain("");
  if (parsed_command_line.HasSwitch(switches::kSdchFilter)) {
    sdch_supported_domain =
        parsed_command_line.GetSwitchValueASCII(switches::kSdchFilter);
  } else {
    sdch_trial->AppendGroup("_global_disable_sdch",
                            kSDCH_DISABLE_PROBABILITY);
    int sdch_enabled = sdch_trial->AppendGroup("_global_enable_sdch",
        FieldTrial::kAllRemainingProbability);
    if (sdch_enabled != sdch_trial->group())
      sdch_supported_domain = "never_enabled_sdch_for_any_domain";
  }

  SdchManager sdch_manager;  // Singleton database.
  sdch_manager.set_sdch_fetcher(new SdchDictionaryFetcher);
  sdch_manager.EnableSdchSupport(sdch_supported_domain);

  MetricsService* metrics = InitializeMetrics(parsed_command_line, local_state);
  InstallJankometer(parsed_command_line);

#if defined(OS_WIN) && !defined(GOOGLE_CHROME_BUILD)
  if (parsed_command_line.HasSwitch(switches::kDebugPrint)) {
    printing::PrintedDocument::set_debug_dump_path(
        parsed_command_line.GetSwitchValue(switches::kDebugPrint));
  }
#endif

  HandleTestParameters(parsed_command_line);
  RecordBreakpadStatusUMA(metrics);

  // Stat the directory with the inspector's files so that we can know if we
  // should display the entry in the context menu or not.
  browser_process->CheckForInspectorFiles();

#if defined(OS_CHROMEOS)
  metrics->StartExternalMetrics();
#endif

  if (profile->GetExtensionsService()) {
    // This will initialize bookmarks. Call it after bookmark import is done.
    // See issue 40144.
    profile->GetExtensionsService()->InitEventRouters();
  }

#if defined(OS_WIN)
  // We check this here because if the profile is OTR (chromeos possibility)
  // it won't still be accessible after browser is destroyed.
  bool record_search_engine = is_first_run && !profile->IsOffTheRecord();
#endif

    // ChildProcess:: is a misnomer unless you consider context.  Use
    // of --wait-for-debugger only makes sense when Chrome itself is a
    // child process (e.g. when launched by PyAuto).
  if (parsed_command_line.HasSwitch(switches::kWaitForDebugger)) {
    ChildProcess::WaitForDebugger(L"Browser");
  }

  int result_code = ResultCodes::NORMAL_EXIT;
  if (parameters.ui_task) {
    // We are in test mode. Run one task and enter the main message loop.
    if (pool)
      pool->Recycle();
    parameters.ui_task->Run();
    delete parameters.ui_task;
  } else {
    // We are in regular browser boot sequence. Open initial stabs and enter
    // the main message loop.
    if (browser_init.Start(parsed_command_line, std::wstring(), profile,
                           &result_code)) {
#if (defined(OS_WIN) || defined(OS_LINUX)) && !defined(OS_CHROMEOS)
      // Initialize autoupdate timer. Timer callback costs basically nothing
      // when browser is not in persistent mode, so it's OK to let it ride on
      // the main thread. This needs to be done here because we don't want
      // to start the timer when Chrome is run inside a test harness.
      g_browser_process->StartAutoupdateTimer();
#endif

#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
      // On Linux, the running exe will be updated if an upgrade becomes
      // available while the browser is running.  We need to save the last
      // modified time of the exe, so we can compare to determine if there is
      // an upgrade while the browser is kept alive by a persistent extension.
      Upgrade::SaveLastModifiedTimeOfExe();
#endif

      // Record now as the last successful chrome start.
      GoogleUpdateSettings::SetLastRunTime();
      // Call Recycle() here as late as possible, before going into the loop
      // because Start() will add things to it while creating the main window.
      if (pool)
        pool->Recycle();
      RunUIMessageLoop(browser_process.get());
    }
  }

#if defined(OS_WIN)
  // If it's the first run, log the search engine chosen.  We wait until
  // shutdown because otherwise we can't be sure the user has finished
  // selecting a search engine through the dialog reached from the first run
  // bubble link.
  if (FirstRun::InSearchExperimentLocale() && record_search_engine) {
    const TemplateURL* default_search_engine =
        profile->GetTemplateURLModel()->GetDefaultSearchProvider();
    // Record the search engine chosen.
    if (master_prefs.run_search_engine_experiment) {
      UMA_HISTOGRAM_ENUMERATION(
          "Chrome.SearchSelectExperiment",
          TemplateURLPrepopulateData::GetSearchEngineType(
          default_search_engine),
          TemplateURLPrepopulateData::SEARCH_ENGINE_MAX);
      // If the selection has been randomized, also record the winner by slot.
      if (master_prefs.randomize_search_engine_experiment) {
        size_t engine_pos = profile->GetTemplateURLModel()->
            GetSearchEngineDialogSlot();
        if (engine_pos < 4) {
          std::string experiment_type = "Chrome.SearchSelectExperimentSlot";
          // Nicer in UMA if slots are 1-based.
          experiment_type.push_back('1' + engine_pos);
          UMA_HISTOGRAM_ENUMERATION(
              experiment_type,
              TemplateURLPrepopulateData::GetSearchEngineType(
              default_search_engine),
              TemplateURLPrepopulateData::SEARCH_ENGINE_MAX);
        } else {
          NOTREACHED() << "Invalid search engine selection slot.";
        }
      }
    } else {
      UMA_HISTOGRAM_ENUMERATION(
          "Chrome.SearchSelectExempt",
          TemplateURLPrepopulateData::GetSearchEngineType(
              default_search_engine),
          TemplateURLPrepopulateData::SEARCH_ENGINE_MAX);
    }
  }
#endif

  chrome_browser_net_websocket_experiment::WebSocketExperimentRunner::Stop();

  process_singleton.Cleanup();

  metrics->Stop();

  // browser_shutdown takes care of deleting browser_process, so we need to
  // release it.
  ignore_result(browser_process.release());
  browser_shutdown::Shutdown();

  return result_code;
}