content/browser/browser_main_loop.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/browser/browser_main_loop.h"
   6
   7 #include "base/bind.h"
   8 #include "base/command_line.h"
   9 #include "base/debug/trace_event.h"
  10 #include "base/file_util.h"
  11 #include "base/logging.h"
  12 #include "base/message_loop/message_loop.h"
  13 #include "base/metrics/field_trial.h"
  14 #include "base/metrics/histogram.h"
  15 #include "base/path_service.h"
  16 #include "base/pending_task.h"
  17 #include "base/power_monitor/power_monitor.h"
  18 #include "base/power_monitor/power_monitor_device_source.h"
  19 #include "base/process/process_metrics.h"
  20 #include "base/run_loop.h"
  21 #include "base/strings/string_number_conversions.h"
  22 #include "base/system_monitor/system_monitor.h"
  23 #include "base/thread_task_runner_handle.h"
  24 #include "base/threading/thread_restrictions.h"
  25 #include "base/timer/hi_res_timer_manager.h"
  26 #include "content/browser/browser_thread_impl.h"
  27 #include "content/browser/device_orientation/device_inertial_sensor_service.h"
  28 #include "content/browser/download/save_file_manager.h"
  29 #include "content/browser/gamepad/gamepad_service.h"
  30 #include "content/browser/gpu/browser_gpu_channel_host_factory.h"
  31 #include "content/browser/gpu/compositor_util.h"
  32 #include "content/browser/gpu/gpu_data_manager_impl.h"
  33 #include "content/browser/gpu/gpu_process_host.h"
  34 #include "content/browser/gpu/gpu_process_host_ui_shim.h"
  35 #include "content/browser/histogram_synchronizer.h"
  36 #include "content/browser/loader/resource_dispatcher_host_impl.h"
  37 #include "content/browser/media/capture/audio_mirroring_manager.h"
  38 #include "content/browser/media/media_internals.h"
  39 #include "content/browser/net/browser_online_state_observer.h"
  40 #include "content/browser/plugin_service_impl.h"
  41 #include "content/browser/renderer_host/media/media_stream_manager.h"
  42 #include "content/browser/renderer_host/render_process_host_impl.h"
  43 #include "content/browser/speech/speech_recognition_manager_impl.h"
  44 #include "content/browser/startup_task_runner.h"
  45 #include "content/browser/webui/content_web_ui_controller_factory.h"
  46 #include "content/browser/webui/url_data_manager.h"
  47 #include "content/public/browser/browser_main_parts.h"
  48 #include "content/public/browser/browser_shutdown.h"
  49 #include "content/public/browser/content_browser_client.h"
  50 #include "content/public/browser/render_process_host.h"
  51 #include "content/public/browser/tracing_controller.h"
  52 #include "content/public/common/content_switches.h"
  53 #include "content/public/common/main_function_params.h"
  54 #include "content/public/common/result_codes.h"
  55 #include "crypto/nss_util.h"
  56 #include "media/audio/audio_manager.h"
  57 #include "media/base/media.h"
  58 #include "media/base/user_input_monitor.h"
  59 #include "media/midi/midi_manager.h"
  60 #include "net/base/network_change_notifier.h"
  61 #include "net/socket/client_socket_factory.h"
  62 #include "net/ssl/ssl_config_service.h"
  63 #include "ui/base/clipboard/clipboard.h"
  64
  65 #if defined(USE_AURA)
  66 #include "content/browser/compositor/image_transport_factory.h"
  67 #endif
  68
  69 #if defined(OS_ANDROID)
  70 #include "base/android/jni_android.h"
  71 #include "content/browser/android/browser_startup_controller.h"
  72 #include "content/browser/android/surface_texture_peer_browser_impl.h"
  73 #include "ui/gl/gl_surface.h"
  74 #endif
  75
  76 #if defined(OS_MACOSX) && !defined(OS_IOS)
  77 #include "content/browser/theme_helper_mac.h"
  78 #endif
  79
  80 #if defined(OS_WIN)
  81 #include <windows.h>
  82 #include <commctrl.h>
  83 #include <shellapi.h>
  84
  85 #include "content/browser/system_message_window_win.h"
  86 #include "content/common/sandbox_win.h"
  87 #include "net/base/winsock_init.h"
  88 #include "ui/base/l10n/l10n_util_win.h"
  89 #endif
  90
  91 #if defined(USE_GLIB)
  92 #include <glib-object.h>
  93 #endif
  94
  95 #if defined(OS_LINUX) && defined(USE_UDEV)
  96 #include "content/browser/device_monitor_udev.h"
  97 #elif defined(OS_MACOSX) && !defined(OS_IOS)
  98 #include "content/browser/device_monitor_mac.h"
  99 #endif
 100
 101 #if defined(TOOLKIT_GTK)
 102 #include "ui/gfx/gtk_util.h"
 103 #endif
 104
 105 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 106 #include <sys/stat.h>
 107
 108 #include "content/browser/renderer_host/render_sandbox_host_linux.h"
 109 #include "content/browser/zygote_host/zygote_host_impl_linux.h"
 110 #endif
 111
 112 #if defined(TCMALLOC_TRACE_MEMORY_SUPPORTED)
 113 #include "third_party/tcmalloc/chromium/src/gperftools/heap-profiler.h"
 114 #endif
 115
 116 #if defined(USE_X11)
 117 #include <X11/Xlib.h>
 118 #endif
 119
 120 #if defined(USE_OZONE)
 121 #include "ui/ozone/ozone_platform.h"
 122 #endif
 123
 124 // One of the linux specific headers defines this as a macro.
 125 #ifdef DestroyAll
 126 #undef DestroyAll
 127 #endif
 128
 129 namespace content {
 130 namespace {
 131
 132 #if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
 133 void SetupSandbox(const CommandLine& parsed_command_line) {
 134   TRACE_EVENT0("startup", "SetupSandbox");
 135   // TODO(evanm): move this into SandboxWrapper; I'm just trying to move this
 136   // code en masse out of chrome_main for now.
 137   base::FilePath sandbox_binary;
 138   bool env_chrome_devel_sandbox_set = false;
 139   struct stat st;
 140
 141   const bool want_setuid_sandbox =
 142       !parsed_command_line.HasSwitch(switches::kNoSandbox) &&
 143       !parsed_command_line.HasSwitch(switches::kDisableSetuidSandbox);
 144
 145   if (want_setuid_sandbox) {
 146     base::FilePath exe_dir;
 147     if (PathService::Get(base::DIR_EXE, &exe_dir)) {
 148       base::FilePath sandbox_candidate = exe_dir.AppendASCII("chrome-sandbox");
 149       if (base::PathExists(sandbox_candidate))
 150         sandbox_binary = sandbox_candidate;
 151     }
 152
 153     // In user-managed builds, including development builds, an environment
 154     // variable is required to enable the sandbox. See
 155     // http://code.google.com/p/chromium/wiki/LinuxSUIDSandboxDevelopment
 156     if (sandbox_binary.empty() &&
 157         stat(base::kProcSelfExe, &st) == 0 && st.st_uid == getuid()) {
 158       const char* devel_sandbox_path = getenv("CHROME_DEVEL_SANDBOX");
 159       if (devel_sandbox_path) {
 160         env_chrome_devel_sandbox_set = true;
 161         sandbox_binary = base::FilePath(devel_sandbox_path);
 162       }
 163     }
 164
 165     static const char no_suid_error[] = "Running without the SUID sandbox! See "
 166         "https://code.google.com/p/chromium/wiki/LinuxSUIDSandboxDevelopment "
 167         "for more information on developing with the sandbox on.";
 168     if (sandbox_binary.empty()) {
 169       if (!env_chrome_devel_sandbox_set) {
 170         // This needs to be fatal. Talk to security@chromium.org if you feel
 171         // otherwise.
 172         LOG(FATAL) << no_suid_error;
 173       }
 174
 175       // TODO(jln): an empty CHROME_DEVEL_SANDBOX environment variable (as
 176       // opposed to a non existing one) is not fatal yet. This is needed
 177       // because of existing bots and scripts. Fix it (crbug.com/245376).
 178       LOG(ERROR) << no_suid_error;
 179     }
 180   }
 181
 182   // Tickle the sandbox host and zygote host so they fork now.
 183   RenderSandboxHostLinux::GetInstance()->Init(sandbox_binary.value());
 184   ZygoteHostImpl::GetInstance()->Init(sandbox_binary.value());
 185 }
 186 #endif
 187
 188 #if defined(USE_GLIB)
 189 static void GLibLogHandler(const gchar* log_domain,
 190                            GLogLevelFlags log_level,
 191                            const gchar* message,
 192                            gpointer userdata) {
 193   if (!log_domain)
 194     log_domain = "<unknown>";
 195   if (!message)
 196     message = "<no message>";
 197
 198   if (strstr(message, "Loading IM context type") ||
 199       strstr(message, "wrong ELF class: ELFCLASS64")) {
 200     // http://crbug.com/9643
 201     // Until we have a real 64-bit build or all of these 32-bit package issues
 202     // are sorted out, don't fatal on ELF 32/64-bit mismatch warnings and don't
 203     // spam the user with more than one of them.
 204     static bool alerted = false;
 205     if (!alerted) {
 206       LOG(ERROR) << "Bug 9643: " << log_domain << ": " << message;
 207       alerted = true;
 208     }
 209   } else if (strstr(message, "Unable to retrieve the file info for")) {
 210     LOG(ERROR) << "GTK File code error: " << message;
 211   } else if (strstr(message, "Could not find the icon") &&
 212              strstr(log_domain, "Gtk")) {
 213     LOG(ERROR) << "GTK icon error: " << message;
 214   } else if (strstr(message, "Theme file for default has no") ||
 215              strstr(message, "Theme directory") ||
 216              strstr(message, "theme pixmap") ||
 217              strstr(message, "locate theme engine")) {
 218     LOG(ERROR) << "GTK theme error: " << message;
 219   } else if (strstr(message, "Unable to create Ubuntu Menu Proxy") &&
 220              strstr(log_domain, "<unknown>")) {
 221     LOG(ERROR) << "GTK menu proxy create failed";
 222   } else if (strstr(message, "gtk_drag_dest_leave: assertion")) {
 223     LOG(ERROR) << "Drag destination deleted: http://crbug.com/18557";
 224   } else if (strstr(message, "Out of memory") &&
 225              strstr(log_domain, "<unknown>")) {
 226     LOG(ERROR) << "DBus call timeout or out of memory: "
 227                << "http://crosbug.com/15496";
 228   } else if (strstr(message, "Could not connect: Connection refused") &&
 229              strstr(log_domain, "<unknown>")) {
 230     LOG(ERROR) << "DConf settings backend could not connect to session bus: "
 231                << "http://crbug.com/179797";
 232   } else if (strstr(message, "XDG_RUNTIME_DIR variable not set")) {
 233     LOG(ERROR) << message << " (http://bugs.chromium.org/97293)";
 234   } else if (strstr(message, "Attempting to store changes into") ||
 235              strstr(message, "Attempting to set the permissions of")) {
 236     LOG(ERROR) << message << " (http://bugs.chromium.org/161366)";
 237   } else if (strstr(message, "drawable is not a native X11 window")) {
 238     LOG(ERROR) << message << " (http://bugs.chromium.org/329991)";
 239   } else {
 240     LOG(DFATAL) << log_domain << ": " << message;
 241   }
 242 }
 243
 244 static void SetUpGLibLogHandler() {
 245   // Register GLib-handled assertions to go through our logging system.
 246   const char* kLogDomains[] = { NULL, "Gtk", "Gdk", "GLib", "GLib-GObject" };
 247   for (size_t i = 0; i < arraysize(kLogDomains); i++) {
 248     g_log_set_handler(kLogDomains[i],
 249                       static_cast<GLogLevelFlags>(G_LOG_FLAG_RECURSION |
 250                                                   G_LOG_FLAG_FATAL |
 251                                                   G_LOG_LEVEL_ERROR |
 252                                                   G_LOG_LEVEL_CRITICAL |
 253                                                   G_LOG_LEVEL_WARNING),
 254                       GLibLogHandler,
 255                       NULL);
 256   }
 257 }
 258 #endif
 259
 260 }  // namespace
 261
 262 // The currently-running BrowserMainLoop.  There can be one or zero.
 263 BrowserMainLoop* g_current_browser_main_loop = NULL;
 264
 265 // This is just to be able to keep ShutdownThreadsAndCleanUp out of
 266 // the public interface of BrowserMainLoop.
 267 class BrowserShutdownImpl {
 268  public:
 269   static void ImmediateShutdownAndExitProcess() {
 270     DCHECK(g_current_browser_main_loop);
 271     g_current_browser_main_loop->ShutdownThreadsAndCleanUp();
 272
 273 #if defined(OS_WIN)
 274     // At this point the message loop is still running yet we've shut everything
 275     // down. If any messages are processed we'll likely crash. Exit now.
 276     ExitProcess(RESULT_CODE_NORMAL_EXIT);
 277 #elif defined(OS_POSIX) && !defined(OS_MACOSX)
 278     _exit(RESULT_CODE_NORMAL_EXIT);
 279 #else
 280     NOTIMPLEMENTED();
 281 #endif
 282   }
 283 };
 284
 285 void ImmediateShutdownAndExitProcess() {
 286   BrowserShutdownImpl::ImmediateShutdownAndExitProcess();
 287 }
 288
 289 // For measuring memory usage after each task. Behind a command line flag.
 290 class BrowserMainLoop::MemoryObserver : public base::MessageLoop::TaskObserver {
 291  public:
 292   MemoryObserver() {}
 293   virtual ~MemoryObserver() {}
 294
 295   virtual void WillProcessTask(const base::PendingTask& pending_task) OVERRIDE {
 296   }
 297
 298   virtual void DidProcessTask(const base::PendingTask& pending_task) OVERRIDE {
 299 #if !defined(OS_IOS)  // No ProcessMetrics on IOS.
 300     scoped_ptr<base::ProcessMetrics> process_metrics(
 301         base::ProcessMetrics::CreateProcessMetrics(
 302 #if defined(OS_MACOSX)
 303             base::GetCurrentProcessHandle(), NULL));
 304 #else
 305             base::GetCurrentProcessHandle()));
 306 #endif
 307     size_t private_bytes;
 308     process_metrics->GetMemoryBytes(&private_bytes, NULL);
 309     HISTOGRAM_MEMORY_KB("Memory.BrowserUsed", private_bytes >> 10);
 310 #endif
 311   }
 312  private:
 313   DISALLOW_COPY_AND_ASSIGN(MemoryObserver);
 314 };
 315
 316
 317 // BrowserMainLoop construction / destruction =============================
 318
 319 BrowserMainLoop* BrowserMainLoop::GetInstance() {
 320   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 321   return g_current_browser_main_loop;
 322 }
 323
 324 BrowserMainLoop::BrowserMainLoop(const MainFunctionParams& parameters)
 325     : parameters_(parameters),
 326       parsed_command_line_(parameters.command_line),
 327       result_code_(RESULT_CODE_NORMAL_EXIT),
 328       created_threads_(false),
 329       // ContentMainRunner should have enabled tracing of the browser process
 330       // when kTraceStartup is in the command line.
 331       is_tracing_startup_(
 332           parameters.command_line.HasSwitch(switches::kTraceStartup)) {
 333   DCHECK(!g_current_browser_main_loop);
 334   g_current_browser_main_loop = this;
 335 }
 336
 337 BrowserMainLoop::~BrowserMainLoop() {
 338   DCHECK_EQ(this, g_current_browser_main_loop);
 339 #if !defined(OS_IOS)
 340   ui::Clipboard::DestroyClipboardForCurrentThread();
 341 #endif  // !defined(OS_IOS)
 342   g_current_browser_main_loop = NULL;
 343 }
 344
 345 void BrowserMainLoop::Init() {
 346   TRACE_EVENT0("startup", "BrowserMainLoop::Init")
 347   parts_.reset(
 348       GetContentClient()->browser()->CreateBrowserMainParts(parameters_));
 349 }
 350
 351 // BrowserMainLoop stages ==================================================
 352
 353 void BrowserMainLoop::EarlyInitialization() {
 354   TRACE_EVENT0("startup", "BrowserMainLoop::EarlyInitialization");
 355
 356 #if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
 357   // No thread should be created before this call, as SetupSandbox()
 358   // will end-up using fork().
 359   SetupSandbox(parsed_command_line_);
 360 #endif
 361
 362 #if defined(USE_X11)
 363   if (parsed_command_line_.HasSwitch(switches::kSingleProcess) ||
 364       parsed_command_line_.HasSwitch(switches::kInProcessGPU)) {
 365     if (!XInitThreads()) {
 366       LOG(ERROR) << "Failed to put Xlib into threaded mode.";
 367     }
 368   }
 369 #endif
 370
 371   // GLib's spawning of new processes is buggy, so it's important that at this
 372   // point GLib does not need to start DBUS. Chrome should always start with
 373   // DBUS_SESSION_BUS_ADDRESS properly set. See crbug.com/309093.
 374 #if defined(USE_GLIB)
 375   // g_type_init will be deprecated in 2.36. 2.35 is the development
 376   // version for 2.36, hence do not call g_type_init starting 2.35.
 377   // http://developer.gnome.org/gobject/unstable/gobject-Type-Information.html#g-type-init
 378 #if !GLIB_CHECK_VERSION(2, 35, 0)
 379   // GLib type system initialization. Needed at least for gconf,
 380   // used in net/proxy/proxy_config_service_linux.cc. Most likely
 381   // this is superfluous as gtk_init() ought to do this. It's
 382   // definitely harmless, so retained as a reminder of this
 383   // requirement for gconf.
 384   g_type_init();
 385 #endif
 386
 387 #if !defined(USE_AURA)
 388   gfx::GtkInitFromCommandLine(parsed_command_line_);
 389 #endif
 390
 391   SetUpGLibLogHandler();
 392 #endif
 393
 394   if (parts_)
 395     parts_->PreEarlyInitialization();
 396
 397 #if defined(OS_WIN)
 398   net::EnsureWinsockInit();
 399 #endif
 400
 401 #if !defined(USE_OPENSSL)
 402   // We want to be sure to init NSPR on the main thread.
 403   crypto::EnsureNSPRInit();
 404 #endif  // !defined(USE_OPENSSL)
 405
 406 #if !defined(OS_IOS)
 407   if (parsed_command_line_.HasSwitch(switches::kRendererProcessLimit)) {
 408     std::string limit_string = parsed_command_line_.GetSwitchValueASCII(
 409         switches::kRendererProcessLimit);
 410     size_t process_limit;
 411     if (base::StringToSizeT(limit_string, &process_limit)) {
 412       RenderProcessHost::SetMaxRendererProcessCount(process_limit);
 413     }
 414   }
 415 #endif  // !defined(OS_IOS)
 416
 417   if (parts_)
 418     parts_->PostEarlyInitialization();
 419 }
 420
 421 void BrowserMainLoop::MainMessageLoopStart() {
 422   TRACE_EVENT0("startup", "BrowserMainLoop::MainMessageLoopStart")
 423   if (parts_) {
 424     TRACE_EVENT0("startup",
 425         "BrowserMainLoop::MainMessageLoopStart:PreMainMessageLoopStart");
 426     parts_->PreMainMessageLoopStart();
 427   }
 428
 429 #if defined(OS_WIN)
 430   // If we're running tests (ui_task is non-null), then the ResourceBundle
 431   // has already been initialized.
 432   if (!parameters_.ui_task) {
 433     // Override the configured locale with the user's preferred UI language.
 434     l10n_util::OverrideLocaleWithUILanguageList();
 435   }
 436 #endif
 437
 438   // Create a MessageLoop if one does not already exist for the current thread.
 439   if (!base::MessageLoop::current())
 440     main_message_loop_.reset(new base::MessageLoopForUI);
 441
 442   InitializeMainThread();
 443
 444   {
 445     TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:SystemMonitor")
 446     system_monitor_.reset(new base::SystemMonitor);
 447   }
 448   {
 449     TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:PowerMonitor")
 450     scoped_ptr<base::PowerMonitorSource> power_monitor_source(
 451       new base::PowerMonitorDeviceSource());
 452     power_monitor_.reset(new base::PowerMonitor(power_monitor_source.Pass()));
 453   }
 454   {
 455     TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:HighResTimerManager")
 456     hi_res_timer_manager_.reset(new base::HighResolutionTimerManager);
 457   }
 458   {
 459     TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:NetworkChangeNotifier")
 460     network_change_notifier_.reset(net::NetworkChangeNotifier::Create());
 461   }
 462
 463 #if !defined(OS_IOS)
 464   {
 465     TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:MediaFeatures")
 466     media::InitializeCPUSpecificMediaFeatures();
 467   }
 468   {
 469     TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:AudioMan")
 470     audio_manager_.reset(media::AudioManager::Create(
 471         MediaInternals::GetInstance()));
 472   }
 473   {
 474     TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:MidiManager")
 475     midi_manager_.reset(media::MidiManager::Create());
 476   }
 477   {
 478     TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:ContentWebUIController")
 479     WebUIControllerFactory::RegisterFactory(
 480         ContentWebUIControllerFactory::GetInstance());
 481   }
 482
 483   {
 484     TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:AudioMirroringManager")
 485     audio_mirroring_manager_.reset(new AudioMirroringManager());
 486   }
 487
 488   // Start tracing to a file if needed.
 489   if (is_tracing_startup_) {
 490     TRACE_EVENT0("startup", "BrowserMainLoop::InitStartupTracing")
 491     InitStartupTracing(parsed_command_line_);
 492   }
 493
 494   {
 495     TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:OnlineStateObserver")
 496     online_state_observer_.reset(new BrowserOnlineStateObserver);
 497   }
 498
 499   {
 500     system_stats_monitor_.reset(new base::debug::TraceEventSystemStatsMonitor(
 501         base::ThreadTaskRunnerHandle::Get()));
 502   }
 503 #endif  // !defined(OS_IOS)
 504
 505 #if defined(OS_WIN)
 506   system_message_window_.reset(new SystemMessageWindowWin);
 507 #endif
 508
 509   if (parts_)
 510     parts_->PostMainMessageLoopStart();
 511
 512 #if defined(OS_ANDROID)
 513   {
 514     TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:SurfaceTexturePeer")
 515     SurfaceTexturePeer::InitInstance(new SurfaceTexturePeerBrowserImpl());
 516   }
 517 #endif
 518
 519   if (parsed_command_line_.HasSwitch(switches::kMemoryMetrics)) {
 520     TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:MemoryObserver")
 521     memory_observer_.reset(new MemoryObserver());
 522     base::MessageLoop::current()->AddTaskObserver(memory_observer_.get());
 523   }
 524
 525 #if defined(TCMALLOC_TRACE_MEMORY_SUPPORTED)
 526   trace_memory_controller_.reset(new base::debug::TraceMemoryController(
 527       base::MessageLoop::current()->message_loop_proxy(),
 528       ::HeapProfilerWithPseudoStackStart,
 529       ::HeapProfilerStop,
 530       ::GetHeapProfile));
 531 #endif
 532 }
 533
 534 int BrowserMainLoop::PreCreateThreads() {
 535
 536   if (parts_) {
 537     TRACE_EVENT0("startup",
 538         "BrowserMainLoop::CreateThreads:PreCreateThreads");
 539     result_code_ = parts_->PreCreateThreads();
 540   }
 541
 542 #if defined(ENABLE_PLUGINS)
 543   // Prior to any processing happening on the io thread, we create the
 544   // plugin service as it is predominantly used from the io thread,
 545   // but must be created on the main thread. The service ctor is
 546   // inexpensive and does not invoke the io_thread() accessor.
 547   {
 548     TRACE_EVENT0("startup", "BrowserMainLoop::CreateThreads:PluginService")
 549     PluginService::GetInstance()->Init();
 550   }
 551 #endif
 552
 553 #if !defined(OS_IOS) && (!defined(GOOGLE_CHROME_BUILD) || defined(OS_ANDROID))
 554   // Single-process is an unsupported and not fully tested mode, so
 555   // don't enable it for official Chrome builds (except on Android).
 556   if (parsed_command_line_.HasSwitch(switches::kSingleProcess))
 557     RenderProcessHost::SetRunRendererInProcess(true);
 558 #endif
 559   return result_code_;
 560 }
 561
 562 void BrowserMainLoop::CreateStartupTasks() {
 563   TRACE_EVENT0("startup", "BrowserMainLoop::CreateStartupTasks");
 564
 565   // First time through, we really want to create all the tasks
 566   if (!startup_task_runner_.get()) {
 567 #if defined(OS_ANDROID)
 568     startup_task_runner_ = make_scoped_ptr(new StartupTaskRunner(
 569         base::Bind(&BrowserStartupComplete),
 570         base::MessageLoop::current()->message_loop_proxy()));
 571 #else
 572     startup_task_runner_ = make_scoped_ptr(new StartupTaskRunner(
 573         base::Callback<void(int)>(),
 574         base::MessageLoop::current()->message_loop_proxy()));
 575 #endif
 576     StartupTask pre_create_threads =
 577         base::Bind(&BrowserMainLoop::PreCreateThreads, base::Unretained(this));
 578     startup_task_runner_->AddTask(pre_create_threads);
 579
 580     StartupTask create_threads =
 581         base::Bind(&BrowserMainLoop::CreateThreads, base::Unretained(this));
 582     startup_task_runner_->AddTask(create_threads);
 583
 584     StartupTask browser_thread_started = base::Bind(
 585         &BrowserMainLoop::BrowserThreadsStarted, base::Unretained(this));
 586     startup_task_runner_->AddTask(browser_thread_started);
 587
 588     StartupTask pre_main_message_loop_run = base::Bind(
 589         &BrowserMainLoop::PreMainMessageLoopRun, base::Unretained(this));
 590     startup_task_runner_->AddTask(pre_main_message_loop_run);
 591
 592 #if defined(OS_ANDROID)
 593     if (BrowserMayStartAsynchronously()) {
 594       startup_task_runner_->StartRunningTasksAsync();
 595     }
 596 #endif
 597   }
 598 #if defined(OS_ANDROID)
 599   if (!BrowserMayStartAsynchronously()) {
 600     // A second request for asynchronous startup can be ignored, so
 601     // StartupRunningTasksAsync is only called first time through. If, however,
 602     // this is a request for synchronous startup then it must override any
 603     // previous call for async startup, so we call RunAllTasksNow()
 604     // unconditionally.
 605     startup_task_runner_->RunAllTasksNow();
 606   }
 607 #else
 608   startup_task_runner_->RunAllTasksNow();
 609 #endif
 610 }
 611
 612 int BrowserMainLoop::CreateThreads() {
 613   TRACE_EVENT0("startup", "BrowserMainLoop::CreateThreads");
 614
 615   base::Thread::Options default_options;
 616   base::Thread::Options io_message_loop_options;
 617   io_message_loop_options.message_loop_type = base::MessageLoop::TYPE_IO;
 618   base::Thread::Options ui_message_loop_options;
 619   ui_message_loop_options.message_loop_type = base::MessageLoop::TYPE_UI;
 620
 621   // Start threads in the order they occur in the BrowserThread::ID
 622   // enumeration, except for BrowserThread::UI which is the main
 623   // thread.
 624   //
 625   // Must be size_t so we can increment it.
 626   for (size_t thread_id = BrowserThread::UI + 1;
 627        thread_id < BrowserThread::ID_COUNT;
 628        ++thread_id) {
 629     scoped_ptr<BrowserProcessSubThread>* thread_to_start = NULL;
 630     base::Thread::Options* options = &default_options;
 631
 632     switch (thread_id) {
 633       case BrowserThread::DB:
 634         TRACE_EVENT_BEGIN1("startup",
 635             "BrowserMainLoop::CreateThreads:start",
 636             "Thread", "BrowserThread::DB");
 637         thread_to_start = &db_thread_;
 638         break;
 639       case BrowserThread::FILE_USER_BLOCKING:
 640         TRACE_EVENT_BEGIN1("startup",
 641             "BrowserMainLoop::CreateThreads:start",
 642             "Thread", "BrowserThread::FILE_USER_BLOCKING");
 643         thread_to_start = &file_user_blocking_thread_;
 644         break;
 645       case BrowserThread::FILE:
 646         TRACE_EVENT_BEGIN1("startup",
 647             "BrowserMainLoop::CreateThreads:start",
 648             "Thread", "BrowserThread::FILE");
 649         thread_to_start = &file_thread_;
 650 #if defined(OS_WIN)
 651         // On Windows, the FILE thread needs to be have a UI message loop
 652         // which pumps messages in such a way that Google Update can
 653         // communicate back to us.
 654         options = &ui_message_loop_options;
 655 #else
 656         options = &io_message_loop_options;
 657 #endif
 658         break;
 659       case BrowserThread::PROCESS_LAUNCHER:
 660         TRACE_EVENT_BEGIN1("startup",
 661             "BrowserMainLoop::CreateThreads:start",
 662             "Thread", "BrowserThread::PROCESS_LAUNCHER");
 663         thread_to_start = &process_launcher_thread_;
 664         break;
 665       case BrowserThread::CACHE:
 666         TRACE_EVENT_BEGIN1("startup",
 667             "BrowserMainLoop::CreateThreads:start",
 668             "Thread", "BrowserThread::CACHE");
 669         thread_to_start = &cache_thread_;
 670         options = &io_message_loop_options;
 671         break;
 672       case BrowserThread::IO:
 673         TRACE_EVENT_BEGIN1("startup",
 674             "BrowserMainLoop::CreateThreads:start",
 675             "Thread", "BrowserThread::IO");
 676         thread_to_start = &io_thread_;
 677         options = &io_message_loop_options;
 678         break;
 679       case BrowserThread::UI:
 680       case BrowserThread::ID_COUNT:
 681       default:
 682         NOTREACHED();
 683         break;
 684     }
 685
 686     BrowserThread::ID id = static_cast<BrowserThread::ID>(thread_id);
 687
 688     if (thread_to_start) {
 689       (*thread_to_start).reset(new BrowserProcessSubThread(id));
 690       (*thread_to_start)->StartWithOptions(*options);
 691     } else {
 692       NOTREACHED();
 693     }
 694
 695     TRACE_EVENT_END0("startup", "BrowserMainLoop::CreateThreads:start");
 696
 697   }
 698   created_threads_ = true;
 699   return result_code_;
 700 }
 701
 702 int BrowserMainLoop::PreMainMessageLoopRun() {
 703   if (parts_) {
 704     TRACE_EVENT0("startup",
 705         "BrowserMainLoop::CreateThreads:PreMainMessageLoopRun");
 706     parts_->PreMainMessageLoopRun();
 707   }
 708
 709   // If the UI thread blocks, the whole UI is unresponsive.
 710   // Do not allow disk IO from the UI thread.
 711   base::ThreadRestrictions::SetIOAllowed(false);
 712   base::ThreadRestrictions::DisallowWaiting();
 713   return result_code_;
 714 }
 715
 716 void BrowserMainLoop::RunMainMessageLoopParts() {
 717   TRACE_EVENT_BEGIN_ETW("BrowserMain:MESSAGE_LOOP", 0, "");
 718
 719   bool ran_main_loop = false;
 720   if (parts_)
 721     ran_main_loop = parts_->MainMessageLoopRun(&result_code_);
 722
 723   if (!ran_main_loop)
 724     MainMessageLoopRun();
 725
 726   TRACE_EVENT_END_ETW("BrowserMain:MESSAGE_LOOP", 0, "");
 727 }
 728
 729 void BrowserMainLoop::ShutdownThreadsAndCleanUp() {
 730   if (!created_threads_) {
 731     // Called early, nothing to do
 732     return;
 733   }
 734   TRACE_EVENT0("shutdown", "BrowserMainLoop::ShutdownThreadsAndCleanUp")
 735
 736   // Teardown may start in PostMainMessageLoopRun, and during teardown we
 737   // need to be able to perform IO.
 738   base::ThreadRestrictions::SetIOAllowed(true);
 739   BrowserThread::PostTask(
 740       BrowserThread::IO, FROM_HERE,
 741       base::Bind(base::IgnoreResult(&base::ThreadRestrictions::SetIOAllowed),
 742                  true));
 743
 744   if (RenderProcessHost::run_renderer_in_process())
 745     RenderProcessHostImpl::ShutDownInProcessRenderer();
 746
 747   if (parts_) {
 748     TRACE_EVENT0("shutdown",
 749                  "BrowserMainLoop::Subsystem:PostMainMessageLoopRun");
 750     parts_->PostMainMessageLoopRun();
 751   }
 752
 753   trace_memory_controller_.reset();
 754   system_stats_monitor_.reset();
 755
 756 #if !defined(OS_IOS)
 757   // Destroying the GpuProcessHostUIShims on the UI thread posts a task to
 758   // delete related objects on the GPU thread. This must be done before
 759   // stopping the GPU thread. The GPU thread will close IPC channels to renderer
 760   // processes so this has to happen before stopping the IO thread.
 761   {
 762     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:GPUProcessHostShim");
 763     GpuProcessHostUIShim::DestroyAll();
 764   }
 765   // Cancel pending requests and prevent new requests.
 766   if (resource_dispatcher_host_) {
 767     TRACE_EVENT0("shutdown",
 768                  "BrowserMainLoop::Subsystem:ResourceDispatcherHost");
 769     resource_dispatcher_host_.get()->Shutdown();
 770   }
 771
 772 #if defined(USE_AURA)
 773   {
 774     TRACE_EVENT0("shutdown",
 775                  "BrowserMainLoop::Subsystem:ImageTransportFactory");
 776     ImageTransportFactory::Terminate();
 777   }
 778 #endif
 779
 780 #if defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
 781   ZygoteHostImpl::GetInstance()->TearDownAfterLastChild();
 782 #endif  // defined(OS_POSIX) && !defined(OS_MACOSX) && !defined(OS_ANDROID)
 783
 784   // The device monitors are using |system_monitor_| as dependency, so delete
 785   // them before |system_monitor_| goes away.
 786   // On Mac and windows, the monitor needs to be destroyed on the same thread
 787   // as they were created. On Linux, the monitor will be deleted when IO thread
 788   // goes away.
 789 #if defined(OS_WIN)
 790   system_message_window_.reset();
 791 #elif defined(OS_MACOSX)
 792   device_monitor_mac_.reset();
 793 #endif
 794 #endif  // !defined(OS_IOS)
 795
 796   // Must be size_t so we can subtract from it.
 797   for (size_t thread_id = BrowserThread::ID_COUNT - 1;
 798        thread_id >= (BrowserThread::UI + 1);
 799        --thread_id) {
 800     // Find the thread object we want to stop. Looping over all valid
 801     // BrowserThread IDs and DCHECKing on a missing case in the switch
 802     // statement helps avoid a mismatch between this code and the
 803     // BrowserThread::ID enumeration.
 804     //
 805     // The destruction order is the reverse order of occurrence in the
 806     // BrowserThread::ID list. The rationale for the order is as
 807     // follows (need to be filled in a bit):
 808     //
 809     //
 810     // - The IO thread is the only user of the CACHE thread.
 811     //
 812     // - The PROCESS_LAUNCHER thread must be stopped after IO in case
 813     //   the IO thread posted a task to terminate a process on the
 814     //   process launcher thread.
 815     //
 816     // - (Not sure why DB stops last.)
 817     switch (thread_id) {
 818       case BrowserThread::DB: {
 819           TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:DBThread");
 820           db_thread_.reset();
 821         }
 822         break;
 823       case BrowserThread::FILE_USER_BLOCKING: {
 824           TRACE_EVENT0("shutdown",
 825                        "BrowserMainLoop::Subsystem:FileUserBlockingThread");
 826           file_user_blocking_thread_.reset();
 827         }
 828         break;
 829       case BrowserThread::FILE: {
 830           TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:FileThread");
 831 #if !defined(OS_IOS)
 832           // Clean up state that lives on or uses the file_thread_ before
 833           // it goes away.
 834           if (resource_dispatcher_host_)
 835             resource_dispatcher_host_.get()->save_file_manager()->Shutdown();
 836 #endif  // !defined(OS_IOS)
 837           file_thread_.reset();
 838         }
 839         break;
 840       case BrowserThread::PROCESS_LAUNCHER: {
 841           TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:LauncherThread");
 842           process_launcher_thread_.reset();
 843         }
 844         break;
 845       case BrowserThread::CACHE: {
 846           TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:CacheThread");
 847           cache_thread_.reset();
 848         }
 849         break;
 850       case BrowserThread::IO: {
 851           TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:IOThread");
 852           io_thread_.reset();
 853         }
 854         break;
 855       case BrowserThread::UI:
 856       case BrowserThread::ID_COUNT:
 857       default:
 858         NOTREACHED();
 859         break;
 860     }
 861   }
 862
 863 #if !defined(OS_IOS)
 864   {
 865     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:IndexedDBThread");
 866     indexed_db_thread_.reset();
 867   }
 868 #endif
 869
 870   // Close the blocking I/O pool after the other threads. Other threads such
 871   // as the I/O thread may need to schedule work like closing files or flushing
 872   // data during shutdown, so the blocking pool needs to be available. There
 873   // may also be slow operations pending that will blcok shutdown, so closing
 874   // it here (which will block until required operations are complete) gives
 875   // more head start for those operations to finish.
 876   {
 877     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:ThreadPool");
 878     BrowserThreadImpl::ShutdownThreadPool();
 879   }
 880
 881 #if !defined(OS_IOS)
 882   // Must happen after the IO thread is shutdown since this may be accessed from
 883   // it.
 884   {
 885     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:GPUChannelFactory");
 886     if (BrowserGpuChannelHostFactory::instance())
 887       BrowserGpuChannelHostFactory::Terminate();
 888   }
 889
 890   // Must happen after the I/O thread is shutdown since this class lives on the
 891   // I/O thread and isn't threadsafe.
 892   {
 893     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:GamepadService");
 894     GamepadService::GetInstance()->Terminate();
 895   }
 896   {
 897     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:SensorService");
 898     DeviceInertialSensorService::GetInstance()->Shutdown();
 899   }
 900   {
 901     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:DeleteDataSources");
 902     URLDataManager::DeleteDataSources();
 903   }
 904 #endif  // !defined(OS_IOS)
 905
 906   if (parts_) {
 907     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:PostDestroyThreads");
 908     parts_->PostDestroyThreads();
 909   }
 910 }
 911
 912 void BrowserMainLoop::InitializeMainThread() {
 913   TRACE_EVENT0("startup", "BrowserMainLoop::InitializeMainThread")
 914   const char* kThreadName = "CrBrowserMain";
 915   base::PlatformThread::SetName(kThreadName);
 916   if (main_message_loop_)
 917     main_message_loop_->set_thread_name(kThreadName);
 918
 919   // Register the main thread by instantiating it, but don't call any methods.
 920   main_thread_.reset(
 921       new BrowserThreadImpl(BrowserThread::UI, base::MessageLoop::current()));
 922 }
 923
 924 int BrowserMainLoop::BrowserThreadsStarted() {
 925   TRACE_EVENT0("startup", "BrowserMainLoop::BrowserThreadsStarted")
 926
 927 #if !defined(OS_IOS)
 928   indexed_db_thread_.reset(new base::Thread("IndexedDB"));
 929   indexed_db_thread_->Start();
 930 #endif
 931
 932 #if defined(OS_ANDROID)
 933   // Up the priority of anything that touches with display tasks
 934   // (this thread is UI thread, and io_thread_ is for IPCs).
 935   io_thread_->SetPriority(base::kThreadPriority_Display);
 936   base::PlatformThread::SetThreadPriority(
 937       base::PlatformThread::CurrentHandle(),
 938       base::kThreadPriority_Display);
 939 #endif
 940
 941 #if !defined(OS_IOS)
 942   HistogramSynchronizer::GetInstance();
 943
 944 #if defined(OS_ANDROID)
 945   // On Android, GLSurface::InitializeOneOff() must be called before initalizing
 946   // the GpuDataManagerImpl as it uses the GL bindings. crbug.com/326295
 947   if (!gfx::GLSurface::InitializeOneOff())
 948     LOG(FATAL) << "GLSurface::InitializeOneOff failed";
 949 #endif
 950
 951   // Initialize the GpuDataManager before we set up the MessageLoops because
 952   // otherwise we'll trigger the assertion about doing IO on the UI thread.
 953   GpuDataManagerImpl::GetInstance()->Initialize();
 954
 955   bool always_uses_gpu = IsForceCompositingModeEnabled();
 956   bool established_gpu_channel = false;
 957 #if defined(USE_AURA) || defined(OS_ANDROID)
 958   established_gpu_channel =
 959       !parsed_command_line_.HasSwitch(switches::kDisableGpuProcessPrelaunch) ||
 960       parsed_command_line_.HasSwitch(switches::kSingleProcess) ||
 961       parsed_command_line_.HasSwitch(switches::kInProcessGPU);
 962 #if defined(USE_AURA)
 963   if (!GpuDataManagerImpl::GetInstance()->CanUseGpuBrowserCompositor()) {
 964     established_gpu_channel = always_uses_gpu = false;
 965   }
 966   BrowserGpuChannelHostFactory::Initialize(established_gpu_channel);
 967   ImageTransportFactory::Initialize();
 968 #elif defined(OS_ANDROID)
 969   BrowserGpuChannelHostFactory::Initialize(established_gpu_channel);
 970 #endif
 971 #endif
 972
 973 #if defined(OS_LINUX) && defined(USE_UDEV)
 974   device_monitor_linux_.reset(new DeviceMonitorLinux());
 975 #elif defined(OS_MACOSX)
 976   device_monitor_mac_.reset(new DeviceMonitorMac());
 977 #endif
 978
 979 #if defined(USE_OZONE)
 980   ui::OzonePlatform::Initialize();
 981   ui::EventFactoryOzone::GetInstance()->SetFileTaskRunner(
 982       BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE));
 983 #endif
 984
 985   // RDH needs the IO thread to be created
 986   {
 987     TRACE_EVENT0("startup",
 988       "BrowserMainLoop::BrowserThreadsStarted:InitResourceDispatcherHost");
 989     resource_dispatcher_host_.reset(new ResourceDispatcherHostImpl());
 990   }
 991
 992   // MediaStreamManager needs the IO thread to be created.
 993   {
 994     TRACE_EVENT0("startup",
 995       "BrowserMainLoop::BrowserThreadsStarted:InitMediaStreamManager");
 996     media_stream_manager_.reset(new MediaStreamManager(audio_manager_.get()));
 997   }
 998
 999   {
1000     TRACE_EVENT0("startup",
1001       "BrowserMainLoop::BrowserThreadsStarted:InitSpeechRecognition");
1002     speech_recognition_manager_.reset(new SpeechRecognitionManagerImpl(
1003         audio_manager_.get(), media_stream_manager_.get()));
1004   }
1005
1006   {
1007     TRACE_EVENT0(
1008         "startup",
1009         "BrowserMainLoop::BrowserThreadsStarted::InitUserInputMonitor");
1010     user_input_monitor_ = media::UserInputMonitor::Create(
1011         io_thread_->message_loop_proxy(), main_thread_->message_loop_proxy());
1012   }
1013
1014   // Alert the clipboard class to which threads are allowed to access the
1015   // clipboard:
1016   std::vector<base::PlatformThreadId> allowed_clipboard_threads;
1017   // The current thread is the UI thread.
1018   allowed_clipboard_threads.push_back(base::PlatformThread::CurrentId());
1019 #if defined(OS_WIN)
1020   // On Windows, clipboards are also used on the File or IO threads.
1021   allowed_clipboard_threads.push_back(file_thread_->thread_id());
1022   allowed_clipboard_threads.push_back(io_thread_->thread_id());
1023 #endif
1024   ui::Clipboard::SetAllowedThreads(allowed_clipboard_threads);
1025
1026   // When running the GPU thread in-process, avoid optimistically starting it
1027   // since creating the GPU thread races against creation of the one-and-only
1028   // ChildProcess instance which is created by the renderer thread.
1029   if (GpuDataManagerImpl::GetInstance()->GpuAccessAllowed(NULL) &&
1030       !established_gpu_channel &&
1031       always_uses_gpu &&
1032       !parsed_command_line_.HasSwitch(switches::kDisableGpuProcessPrelaunch) &&
1033       !parsed_command_line_.HasSwitch(switches::kSingleProcess) &&
1034       !parsed_command_line_.HasSwitch(switches::kInProcessGPU)) {
1035     TRACE_EVENT_INSTANT0("gpu", "Post task to launch GPU process",
1036                          TRACE_EVENT_SCOPE_THREAD);
1037     BrowserThread::PostTask(
1038         BrowserThread::IO, FROM_HERE, base::Bind(
1039             base::IgnoreResult(&GpuProcessHost::Get),
1040             GpuProcessHost::GPU_PROCESS_KIND_SANDBOXED,
1041             CAUSE_FOR_GPU_LAUNCH_BROWSER_STARTUP));
1042   }
1043
1044 #if defined(OS_MACOSX)
1045   ThemeHelperMac::GetInstance();
1046 #endif
1047 #endif  // !defined(OS_IOS)
1048
1049   return result_code_;
1050 }
1051
1052 void BrowserMainLoop::InitializeToolkit() {
1053   TRACE_EVENT0("startup", "BrowserMainLoop::InitializeToolkit")
1054   // TODO(evan): this function is rather subtle, due to the variety
1055   // of intersecting ifdefs we have.  To keep it easy to follow, there
1056   // are no #else branches on any #ifs.
1057   // TODO(stevenjb): Move platform specific code into platform specific Parts
1058   // (Need to add InitializeToolkit stage to BrowserParts).
1059   // See also GTK setup in EarlyInitialization, above, and associated comments.
1060
1061 #if defined(TOOLKIT_GTK)
1062   // It is important for this to happen before the first run dialog, as it
1063   // styles the dialog as well.
1064   gfx::InitRCStyles();
1065 #endif
1066
1067 #if defined(OS_WIN)
1068   // Init common control sex.
1069   INITCOMMONCONTROLSEX config;
1070   config.dwSize = sizeof(config);
1071   config.dwICC = ICC_WIN95_CLASSES;
1072   if (!InitCommonControlsEx(&config))
1073     LOG_GETLASTERROR(FATAL);
1074 #endif
1075
1076   if (parts_)
1077     parts_->ToolkitInitialized();
1078 }
1079
1080 void BrowserMainLoop::MainMessageLoopRun() {
1081 #if defined(OS_ANDROID)
1082   // Android's main message loop is the Java message loop.
1083   NOTREACHED();
1084 #else
1085   DCHECK(base::MessageLoopForUI::IsCurrent());
1086   if (parameters_.ui_task)
1087     base::MessageLoopForUI::current()->PostTask(FROM_HERE,
1088                                                 *parameters_.ui_task);
1089
1090   base::RunLoop run_loop;
1091   run_loop.Run();
1092 #endif
1093 }
1094
1095 void BrowserMainLoop::InitStartupTracing(const CommandLine& command_line) {
1096   DCHECK(is_tracing_startup_);
1097
1098   base::FilePath trace_file = command_line.GetSwitchValuePath(
1099       switches::kTraceStartupFile);
1100   // trace_file = "none" means that startup events will show up for the next
1101   // begin/end tracing (via about:tracing or AutomationProxy::BeginTracing/
1102   // EndTracing, for example).
1103   if (trace_file == base::FilePath().AppendASCII("none"))
1104     return;
1105
1106   if (trace_file.empty()) {
1107     // Default to saving the startup trace into the current dir.
1108     trace_file = base::FilePath().AppendASCII("chrometrace.log");
1109   }
1110
1111   std::string delay_str = command_line.GetSwitchValueASCII(
1112       switches::kTraceStartupDuration);
1113   int delay_secs = 5;
1114   if (!delay_str.empty() && !base::StringToInt(delay_str, &delay_secs)) {
1115     DLOG(WARNING) << "Could not parse --" << switches::kTraceStartupDuration
1116         << "=" << delay_str << " defaulting to 5 (secs)";
1117     delay_secs = 5;
1118   }
1119
1120   BrowserThread::PostDelayedTask(
1121       BrowserThread::UI, FROM_HERE,
1122       base::Bind(&BrowserMainLoop::EndStartupTracing,
1123                  base::Unretained(this), trace_file),
1124       base::TimeDelta::FromSeconds(delay_secs));
1125 }
1126
1127 void BrowserMainLoop::EndStartupTracing(const base::FilePath& trace_file) {
1128   is_tracing_startup_ = false;
1129   TracingController::GetInstance()->DisableRecording(
1130       trace_file, TracingController::TracingFileResultCallback());
1131 }
1132
1133 }  // namespace content