src/chrome/browser/media/media_capture_devices_dispatcher.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 "chrome/browser/media/media_capture_devices_dispatcher.h"
   6
   7 #include "apps/app_window.h"
   8 #include "apps/app_window_registry.h"
   9 #include "base/command_line.h"
  10 #include "base/logging.h"
  11 #include "base/metrics/field_trial.h"
  12 #include "base/prefs/pref_service.h"
  13 #include "base/prefs/scoped_user_pref_update.h"
  14 #include "base/sha1.h"
  15 #include "base/strings/string_number_conversions.h"
  16 #include "base/strings/string_util.h"
  17 #include "base/strings/utf_string_conversions.h"
  18 #include "chrome/browser/extensions/api/tab_capture/tab_capture_registry.h"
  19 #include "chrome/browser/media/desktop_streams_registry.h"
  20 #include "chrome/browser/media/media_stream_capture_indicator.h"
  21 #include "chrome/browser/media/media_stream_infobar_delegate.h"
  22 #include "chrome/browser/profiles/profile.h"
  23 #include "chrome/browser/ui/browser.h"
  24 #include "chrome/browser/ui/browser_finder.h"
  25 #include "chrome/browser/ui/browser_window.h"
  26 #include "chrome/browser/ui/screen_capture_notification_ui.h"
  27 #include "chrome/browser/ui/simple_message_box.h"
  28 #include "chrome/browser/ui/website_settings/permission_bubble_manager.h"
  29 #include "chrome/common/chrome_switches.h"
  30 #include "chrome/common/chrome_version_info.h"
  31 #include "chrome/common/pref_names.h"
  32 #include "components/pref_registry/pref_registry_syncable.h"
  33 #include "content/public/browser/browser_thread.h"
  34 #include "content/public/browser/desktop_media_id.h"
  35 #include "content/public/browser/media_capture_devices.h"
  36 #include "content/public/browser/notification_service.h"
  37 #include "content/public/browser/notification_source.h"
  38 #include "content/public/browser/notification_types.h"
  39 #include "content/public/browser/render_frame_host.h"
  40 #include "content/public/browser/web_contents.h"
  41 #include "content/public/common/media_stream_request.h"
  42 #include "extensions/common/constants.h"
  43 #include "extensions/common/extension.h"
  44 #include "extensions/common/permissions/permissions_data.h"
  45 #include "grit/generated_resources.h"
  46 #include "media/audio/audio_manager_base.h"
  47 #include "media/base/media_switches.h"
  48 #include "net/base/net_util.h"
  49 #include "third_party/webrtc/modules/desktop_capture/desktop_capture_types.h"
  50 #include "ui/base/l10n/l10n_util.h"
  51
  52 #if defined(OS_CHROMEOS)
  53 #include "ash/shell.h"
  54 #endif  // defined(OS_CHROMEOS)
  55
  56 // Only do audio stream monitoring for platforms that use it for the tab media
  57 // indicator UI or the OOM killer.
  58 #if !defined(OS_ANDROID) && !defined(OS_IOS)
  59 #define AUDIO_STREAM_MONITORING
  60 #include "chrome/browser/media/audio_stream_monitor.h"
  61 #endif  // !defined(OS_ANDROID) && !defined(OS_IOS)
  62
  63 using content::BrowserThread;
  64 using content::MediaCaptureDevices;
  65 using content::MediaStreamDevices;
  66
  67 namespace {
  68
  69 // A finch experiment to enable the permission bubble for media requests only.
  70 bool MediaStreamPermissionBubbleExperimentEnabled() {
  71   const std::string group =
  72       base::FieldTrialList::FindFullName("MediaStreamPermissionBubble");
  73   if (group == "enabled")
  74     return true;
  75
  76   return false;
  77 }
  78
  79 // Finds a device in |devices| that has |device_id|, or NULL if not found.
  80 const content::MediaStreamDevice* FindDeviceWithId(
  81     const content::MediaStreamDevices& devices,
  82     const std::string& device_id) {
  83   content::MediaStreamDevices::const_iterator iter = devices.begin();
  84   for (; iter != devices.end(); ++iter) {
  85     if (iter->id == device_id) {
  86       return &(*iter);
  87     }
  88   }
  89   return NULL;
  90 }
  91
  92 // This is a short-term solution to grant camera and/or microphone access to
  93 // extensions:
  94 // 1. Virtual keyboard extension.
  95 // 2. Google Voice Search Hotword extension.
  96 // 3. Flutter gesture recognition extension.
  97 // 4. TODO(smus): Airbender experiment 1.
  98 // 5. TODO(smus): Airbender experiment 2.
  99 // Once http://crbug.com/292856 is fixed, remove this whitelist.
 100 bool IsMediaRequestWhitelistedForExtension(
 101     const extensions::Extension* extension) {
 102   return extension->id() == "mppnpdlheglhdfmldimlhpnegondlapf" ||
 103       extension->id() == "bepbmhgboaologfdajaanbcjmnhjmhfn" ||
 104       extension->id() == "jokbpnebhdcladagohdnfgjcpejggllo" ||
 105       extension->id() == "clffjmdilanldobdnedchkdbofoimcgb" ||
 106       extension->id() == "nnckehldicaciogcbchegobnafnjkcne";
 107 }
 108
 109 bool IsBuiltInExtension(const GURL& origin) {
 110   return
 111       // Feedback Extension.
 112       origin.spec() == "chrome-extension://gfdkimpbcpahaombhbimeihdjnejgicl/";
 113 }
 114
 115 // Returns true of the security origin is associated with casting.
 116 bool IsOriginForCasting(const GURL& origin) {
 117 #if defined(OFFICIAL_BUILD)
 118   // Whitelisted tab casting extensions.
 119   return
 120       // Dev
 121       origin.spec() == "chrome-extension://enhhojjnijigcajfphajepfemndkmdlo/" ||
 122       // Canary
 123       origin.spec() == "chrome-extension://hfaagokkkhdbgiakmmlclaapfelnkoah/" ||
 124       // Beta (internal)
 125       origin.spec() == "chrome-extension://fmfcbgogabcbclcofgocippekhfcmgfj/" ||
 126       // Google Cast Beta
 127       origin.spec() == "chrome-extension://dliochdbjfkdbacpmhlcpmleaejidimm/" ||
 128       // Google Cast Stable
 129       origin.spec() == "chrome-extension://boadgeojelhgndaghljhdicfkmllpafd/";
 130 #else
 131   return false;
 132 #endif
 133 }
 134
 135 // Helper to get title of the calling application shown in the screen capture
 136 // notification.
 137 base::string16 GetApplicationTitle(content::WebContents* web_contents,
 138                                    const extensions::Extension* extension) {
 139   // Use extension name as title for extensions and host/origin for drive-by
 140   // web.
 141   std::string title;
 142   if (extension) {
 143     title = extension->name();
 144   } else {
 145     GURL url = web_contents->GetURL();
 146     title = url.SchemeIsSecure() ? net::GetHostAndOptionalPort(url)
 147                                  : url.GetOrigin().spec();
 148   }
 149   return base::UTF8ToUTF16(title);
 150 }
 151
 152 // Helper to get list of media stream devices for desktop capture in |devices|.
 153 // Registers to display notification if |display_notification| is true.
 154 // Returns an instance of MediaStreamUI to be passed to content layer.
 155 scoped_ptr<content::MediaStreamUI> GetDevicesForDesktopCapture(
 156     content::MediaStreamDevices& devices,
 157     content::DesktopMediaID media_id,
 158     bool capture_audio,
 159     bool display_notification,
 160     const base::string16& application_title,
 161     const base::string16& registered_extension_name) {
 162   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 163   scoped_ptr<content::MediaStreamUI> ui;
 164
 165   // Add selected desktop source to the list.
 166   devices.push_back(content::MediaStreamDevice(
 167       content::MEDIA_DESKTOP_VIDEO_CAPTURE, media_id.ToString(), "Screen"));
 168   if (capture_audio) {
 169     // Use the special loopback device ID for system audio capture.
 170     devices.push_back(content::MediaStreamDevice(
 171         content::MEDIA_LOOPBACK_AUDIO_CAPTURE,
 172         media::AudioManagerBase::kLoopbackInputDeviceId, "System Audio"));
 173   }
 174
 175   // If required, register to display the notification for stream capture.
 176   if (display_notification) {
 177     if (application_title == registered_extension_name) {
 178       ui = ScreenCaptureNotificationUI::Create(l10n_util::GetStringFUTF16(
 179           IDS_MEDIA_SCREEN_CAPTURE_NOTIFICATION_TEXT,
 180           application_title));
 181     } else {
 182       ui = ScreenCaptureNotificationUI::Create(l10n_util::GetStringFUTF16(
 183           IDS_MEDIA_SCREEN_CAPTURE_NOTIFICATION_TEXT_DELEGATED,
 184           registered_extension_name,
 185           application_title));
 186     }
 187   }
 188
 189   return ui.Pass();
 190 }
 191
 192 #if defined(AUDIO_STREAM_MONITORING)
 193
 194 AudioStreamMonitor* AudioStreamMonitorFromRenderFrame(
 195     int render_process_id,
 196     int render_frame_id) {
 197   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 198   content::WebContents* const web_contents =
 199       content::WebContents::FromRenderFrameHost(
 200           content::RenderFrameHost::FromID(render_process_id, render_frame_id));
 201   if (!web_contents)
 202     return NULL;
 203   return AudioStreamMonitor::FromWebContents(web_contents);
 204 }
 205
 206 void StartAudioStreamMonitoringOnUIThread(
 207     int render_process_id,
 208     int render_frame_id,
 209     int stream_id,
 210     const AudioStreamMonitor::ReadPowerAndClipCallback& read_power_callback) {
 211   AudioStreamMonitor* const audio_stream_monitor =
 212       AudioStreamMonitorFromRenderFrame(render_process_id, render_frame_id);
 213   if (audio_stream_monitor)
 214     audio_stream_monitor->StartMonitoringStream(stream_id, read_power_callback);
 215 }
 216
 217 void StopAudioStreamMonitoringOnUIThread(
 218     int render_process_id,
 219     int render_frame_id,
 220     int stream_id) {
 221   AudioStreamMonitor* const audio_stream_monitor =
 222       AudioStreamMonitorFromRenderFrame(render_process_id, render_frame_id);
 223   if (audio_stream_monitor)
 224     audio_stream_monitor->StopMonitoringStream(stream_id);
 225 }
 226
 227 #endif  // defined(AUDIO_STREAM_MONITORING)
 228
 229 #if !defined(OS_ANDROID)
 230 // Find browser or app window from a given |web_contents|.
 231 gfx::NativeWindow FindParentWindowForWebContents(
 232     content::WebContents* web_contents) {
 233   Browser* browser = chrome::FindBrowserWithWebContents(web_contents);
 234   if (browser && browser->window())
 235     return browser->window()->GetNativeWindow();
 236
 237   const apps::AppWindowRegistry::AppWindowList& window_list =
 238       apps::AppWindowRegistry::Get(
 239           web_contents->GetBrowserContext())->app_windows();
 240   for (apps::AppWindowRegistry::AppWindowList::const_iterator iter =
 241            window_list.begin();
 242        iter != window_list.end(); ++iter) {
 243     if ((*iter)->web_contents() == web_contents)
 244       return (*iter)->GetNativeWindow();
 245   }
 246
 247   return NULL;
 248 }
 249 #endif
 250
 251 }  // namespace
 252
 253 MediaCaptureDevicesDispatcher::PendingAccessRequest::PendingAccessRequest(
 254     const content::MediaStreamRequest& request,
 255     const content::MediaResponseCallback& callback)
 256     : request(request),
 257       callback(callback) {
 258 }
 259
 260 MediaCaptureDevicesDispatcher::PendingAccessRequest::~PendingAccessRequest() {}
 261
 262 MediaCaptureDevicesDispatcher* MediaCaptureDevicesDispatcher::GetInstance() {
 263   return Singleton<MediaCaptureDevicesDispatcher>::get();
 264 }
 265
 266 MediaCaptureDevicesDispatcher::MediaCaptureDevicesDispatcher()
 267     : is_device_enumeration_disabled_(false),
 268       media_stream_capture_indicator_(new MediaStreamCaptureIndicator()) {
 269   // MediaCaptureDevicesDispatcher is a singleton. It should be created on
 270   // UI thread. Otherwise, it will not receive
 271   // content::NOTIFICATION_WEB_CONTENTS_DESTROYED, and that will result in
 272   // possible use after free.
 273   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 274   notifications_registrar_.Add(
 275       this, content::NOTIFICATION_WEB_CONTENTS_DESTROYED,
 276       content::NotificationService::AllSources());
 277
 278   // AVFoundation is used for video/audio device monitoring and video capture in
 279   // Mac. Experimentally, connect it in Canary and Unkown (developer builds).
 280 #if defined(OS_MACOSX)
 281   chrome::VersionInfo::Channel channel = chrome::VersionInfo::GetChannel();
 282   if (channel == chrome::VersionInfo::CHANNEL_CANARY ||
 283       channel == chrome::VersionInfo::CHANNEL_UNKNOWN) {
 284     CommandLine::ForCurrentProcess()->AppendSwitch(
 285         switches::kEnableAVFoundation);
 286   }
 287 #endif
 288 }
 289
 290 MediaCaptureDevicesDispatcher::~MediaCaptureDevicesDispatcher() {}
 291
 292 void MediaCaptureDevicesDispatcher::RegisterProfilePrefs(
 293     user_prefs::PrefRegistrySyncable* registry) {
 294   registry->RegisterStringPref(
 295       prefs::kDefaultAudioCaptureDevice,
 296       std::string(),
 297       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 298   registry->RegisterStringPref(
 299       prefs::kDefaultVideoCaptureDevice,
 300       std::string(),
 301       user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
 302 }
 303
 304 void MediaCaptureDevicesDispatcher::AddObserver(Observer* observer) {
 305   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 306   if (!observers_.HasObserver(observer))
 307     observers_.AddObserver(observer);
 308 }
 309
 310 void MediaCaptureDevicesDispatcher::RemoveObserver(Observer* observer) {
 311   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 312   observers_.RemoveObserver(observer);
 313 }
 314
 315 const MediaStreamDevices&
 316 MediaCaptureDevicesDispatcher::GetAudioCaptureDevices() {
 317   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 318   if (is_device_enumeration_disabled_ || !test_audio_devices_.empty())
 319     return test_audio_devices_;
 320
 321   return MediaCaptureDevices::GetInstance()->GetAudioCaptureDevices();
 322 }
 323
 324 const MediaStreamDevices&
 325 MediaCaptureDevicesDispatcher::GetVideoCaptureDevices() {
 326   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 327   if (is_device_enumeration_disabled_ || !test_video_devices_.empty())
 328     return test_video_devices_;
 329
 330   return MediaCaptureDevices::GetInstance()->GetVideoCaptureDevices();
 331 }
 332
 333 void MediaCaptureDevicesDispatcher::Observe(
 334     int type,
 335     const content::NotificationSource& source,
 336     const content::NotificationDetails& details) {
 337   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 338   if (type == content::NOTIFICATION_WEB_CONTENTS_DESTROYED) {
 339     content::WebContents* web_contents =
 340         content::Source<content::WebContents>(source).ptr();
 341     pending_requests_.erase(web_contents);
 342   }
 343 }
 344
 345 void MediaCaptureDevicesDispatcher::ProcessMediaAccessRequest(
 346     content::WebContents* web_contents,
 347     const content::MediaStreamRequest& request,
 348     const content::MediaResponseCallback& callback,
 349     const extensions::Extension* extension) {
 350   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 351
 352   if (request.video_type == content::MEDIA_DESKTOP_VIDEO_CAPTURE ||
 353       request.audio_type == content::MEDIA_LOOPBACK_AUDIO_CAPTURE) {
 354     ProcessDesktopCaptureAccessRequest(
 355         web_contents, request, callback, extension);
 356   } else if (request.video_type == content::MEDIA_TAB_VIDEO_CAPTURE ||
 357              request.audio_type == content::MEDIA_TAB_AUDIO_CAPTURE) {
 358     ProcessTabCaptureAccessRequest(
 359         web_contents, request, callback, extension);
 360   } else if (extension && (extension->is_platform_app() ||
 361                            IsMediaRequestWhitelistedForExtension(extension))) {
 362     // For extensions access is approved based on extension permissions.
 363     ProcessMediaAccessRequestFromPlatformAppOrExtension(
 364         web_contents, request, callback, extension);
 365   } else {
 366     ProcessRegularMediaAccessRequest(web_contents, request, callback);
 367   }
 368 }
 369
 370 void MediaCaptureDevicesDispatcher::ProcessDesktopCaptureAccessRequest(
 371     content::WebContents* web_contents,
 372     const content::MediaStreamRequest& request,
 373     const content::MediaResponseCallback& callback,
 374     const extensions::Extension* extension) {
 375   content::MediaStreamDevices devices;
 376   scoped_ptr<content::MediaStreamUI> ui;
 377
 378   if (request.video_type != content::MEDIA_DESKTOP_VIDEO_CAPTURE) {
 379     callback.Run(devices, content::MEDIA_DEVICE_INVALID_STATE, ui.Pass());
 380     return;
 381   }
 382
 383   // If the device id wasn't specified then this is a screen capture request
 384   // (i.e. chooseDesktopMedia() API wasn't used to generate device id).
 385   if (request.requested_video_device_id.empty()) {
 386     ProcessScreenCaptureAccessRequest(
 387         web_contents, request, callback, extension);
 388     return;
 389   }
 390
 391   // The extension name that the stream is registered with.
 392   std::string original_extension_name;
 393   // Resolve DesktopMediaID for the specified device id.
 394   content::DesktopMediaID media_id =
 395       GetDesktopStreamsRegistry()->RequestMediaForStreamId(
 396           request.requested_video_device_id, request.render_process_id,
 397           request.render_view_id, request.security_origin,
 398           &original_extension_name);
 399
 400   // Received invalid device id.
 401   if (media_id.type == content::DesktopMediaID::TYPE_NONE) {
 402     callback.Run(devices, content::MEDIA_DEVICE_INVALID_STATE, ui.Pass());
 403     return;
 404   }
 405
 406   bool loopback_audio_supported = false;
 407 #if defined(USE_CRAS) || defined(OS_WIN)
 408   // Currently loopback audio capture is supported only on Windows and ChromeOS.
 409   loopback_audio_supported = true;
 410 #endif
 411
 412   // Audio is only supported for screen capture streams.
 413   bool capture_audio =
 414       (media_id.type == content::DesktopMediaID::TYPE_SCREEN &&
 415        request.audio_type == content::MEDIA_LOOPBACK_AUDIO_CAPTURE &&
 416        loopback_audio_supported);
 417
 418   ui = GetDevicesForDesktopCapture(
 419       devices, media_id, capture_audio, true,
 420       GetApplicationTitle(web_contents, extension),
 421       base::UTF8ToUTF16(original_extension_name));
 422
 423   callback.Run(devices, content::MEDIA_DEVICE_OK, ui.Pass());
 424 }
 425
 426 void MediaCaptureDevicesDispatcher::ProcessScreenCaptureAccessRequest(
 427     content::WebContents* web_contents,
 428     const content::MediaStreamRequest& request,
 429     const content::MediaResponseCallback& callback,
 430     const extensions::Extension* extension) {
 431   content::MediaStreamDevices devices;
 432   scoped_ptr<content::MediaStreamUI> ui;
 433
 434   DCHECK_EQ(request.video_type, content::MEDIA_DESKTOP_VIDEO_CAPTURE);
 435
 436   bool loopback_audio_supported = false;
 437 #if defined(USE_CRAS) || defined(OS_WIN)
 438   // Currently loopback audio capture is supported only on Windows and ChromeOS.
 439   loopback_audio_supported = true;
 440 #endif
 441
 442   const bool component_extension =
 443       extension && extension->location() == extensions::Manifest::COMPONENT;
 444
 445   const bool screen_capture_enabled =
 446       CommandLine::ForCurrentProcess()->HasSwitch(
 447           switches::kEnableUserMediaScreenCapturing) ||
 448       IsOriginForCasting(request.security_origin) ||
 449       IsBuiltInExtension(request.security_origin);
 450
 451   const bool origin_is_secure =
 452       request.security_origin.SchemeIsSecure() ||
 453       request.security_origin.SchemeIs(extensions::kExtensionScheme) ||
 454       CommandLine::ForCurrentProcess()->HasSwitch(
 455           switches::kAllowHttpScreenCapture);
 456
 457   // Approve request only when the following conditions are met:
 458   //  1. Screen capturing is enabled via command line switch or white-listed for
 459   //     the given origin.
 460   //  2. Request comes from a page with a secure origin or from an extension.
 461   if (screen_capture_enabled && origin_is_secure) {
 462     // Get title of the calling application prior to showing the message box.
 463     // chrome::ShowMessageBox() starts a nested message loop which may allow
 464     // |web_contents| to be destroyed on the UI thread before the message box
 465     // is closed. See http://crbug.com/326690.
 466     base::string16 application_title =
 467         GetApplicationTitle(web_contents, extension);
 468 #if !defined(OS_ANDROID)
 469     gfx::NativeWindow parent_window =
 470         FindParentWindowForWebContents(web_contents);
 471 #else
 472     gfx::NativeWindow parent_window = NULL;
 473 #endif
 474     web_contents = NULL;
 475
 476     // For component extensions, bypass message box.
 477     bool user_approved = false;
 478     if (!component_extension) {
 479       base::string16 application_name = base::UTF8ToUTF16(
 480           extension ? extension->name() : request.security_origin.spec());
 481       base::string16 confirmation_text = l10n_util::GetStringFUTF16(
 482           request.audio_type == content::MEDIA_NO_SERVICE ?
 483               IDS_MEDIA_SCREEN_CAPTURE_CONFIRMATION_TEXT :
 484               IDS_MEDIA_SCREEN_AND_AUDIO_CAPTURE_CONFIRMATION_TEXT,
 485           application_name);
 486       chrome::MessageBoxResult result = chrome::ShowMessageBox(
 487           parent_window,
 488           l10n_util::GetStringFUTF16(
 489               IDS_MEDIA_SCREEN_CAPTURE_CONFIRMATION_TITLE, application_name),
 490           confirmation_text,
 491           chrome::MESSAGE_BOX_TYPE_QUESTION);
 492       user_approved = (result == chrome::MESSAGE_BOX_RESULT_YES);
 493     }
 494
 495     if (user_approved || component_extension) {
 496       content::DesktopMediaID screen_id;
 497 #if defined(OS_CHROMEOS)
 498       screen_id = content::DesktopMediaID::RegisterAuraWindow(
 499           ash::Shell::GetInstance()->GetPrimaryRootWindow());
 500 #else  // defined(OS_CHROMEOS)
 501       screen_id =
 502           content::DesktopMediaID(content::DesktopMediaID::TYPE_SCREEN,
 503                                   webrtc::kFullDesktopScreenId);
 504 #endif  // !defined(OS_CHROMEOS)
 505
 506       bool capture_audio =
 507           (request.audio_type == content::MEDIA_LOOPBACK_AUDIO_CAPTURE &&
 508            loopback_audio_supported);
 509
 510       // Unless we're being invoked from a component extension, register to
 511       // display the notification for stream capture.
 512       bool display_notification = !component_extension;
 513
 514       ui = GetDevicesForDesktopCapture(devices, screen_id, capture_audio,
 515                                        display_notification, application_title,
 516                                        application_title);
 517     }
 518   }
 519
 520   callback.Run(
 521     devices,
 522     devices.empty() ? content::MEDIA_DEVICE_INVALID_STATE :
 523                       content::MEDIA_DEVICE_OK,
 524     ui.Pass());
 525 }
 526
 527 void MediaCaptureDevicesDispatcher::ProcessTabCaptureAccessRequest(
 528     content::WebContents* web_contents,
 529     const content::MediaStreamRequest& request,
 530     const content::MediaResponseCallback& callback,
 531     const extensions::Extension* extension) {
 532   content::MediaStreamDevices devices;
 533   scoped_ptr<content::MediaStreamUI> ui;
 534
 535 #if defined(OS_ANDROID)
 536   // Tab capture is not supported on Android.
 537   callback.Run(devices, content::MEDIA_DEVICE_TAB_CAPTURE_FAILURE, ui.Pass());
 538 #else  // defined(OS_ANDROID)
 539   Profile* profile =
 540       Profile::FromBrowserContext(web_contents->GetBrowserContext());
 541   extensions::TabCaptureRegistry* tab_capture_registry =
 542       extensions::TabCaptureRegistry::Get(profile);
 543   if (!tab_capture_registry) {
 544     NOTREACHED();
 545     callback.Run(devices, content::MEDIA_DEVICE_INVALID_STATE, ui.Pass());
 546     return;
 547   }
 548   bool tab_capture_allowed =
 549       tab_capture_registry->VerifyRequest(request.render_process_id,
 550                                           request.render_view_id);
 551
 552   if (request.audio_type == content::MEDIA_TAB_AUDIO_CAPTURE &&
 553       tab_capture_allowed &&
 554       extension->permissions_data()->HasAPIPermission(
 555           extensions::APIPermission::kTabCapture)) {
 556     devices.push_back(content::MediaStreamDevice(
 557         content::MEDIA_TAB_AUDIO_CAPTURE, std::string(), std::string()));
 558   }
 559
 560   if (request.video_type == content::MEDIA_TAB_VIDEO_CAPTURE &&
 561       tab_capture_allowed &&
 562       extension->permissions_data()->HasAPIPermission(
 563           extensions::APIPermission::kTabCapture)) {
 564     devices.push_back(content::MediaStreamDevice(
 565         content::MEDIA_TAB_VIDEO_CAPTURE, std::string(), std::string()));
 566   }
 567
 568   if (!devices.empty()) {
 569     ui = media_stream_capture_indicator_->RegisterMediaStream(
 570         web_contents, devices);
 571   }
 572   callback.Run(
 573     devices,
 574     devices.empty() ? content::MEDIA_DEVICE_INVALID_STATE :
 575                       content::MEDIA_DEVICE_OK,
 576     ui.Pass());
 577 #endif  // !defined(OS_ANDROID)
 578 }
 579
 580 void MediaCaptureDevicesDispatcher::
 581     ProcessMediaAccessRequestFromPlatformAppOrExtension(
 582         content::WebContents* web_contents,
 583         const content::MediaStreamRequest& request,
 584         const content::MediaResponseCallback& callback,
 585         const extensions::Extension* extension) {
 586   content::MediaStreamDevices devices;
 587   Profile* profile =
 588       Profile::FromBrowserContext(web_contents->GetBrowserContext());
 589
 590   if (request.audio_type == content::MEDIA_DEVICE_AUDIO_CAPTURE &&
 591       extension->permissions_data()->HasAPIPermission(
 592           extensions::APIPermission::kAudioCapture)) {
 593     GetDefaultDevicesForProfile(profile, true, false, &devices);
 594   }
 595
 596   if (request.video_type == content::MEDIA_DEVICE_VIDEO_CAPTURE &&
 597       extension->permissions_data()->HasAPIPermission(
 598           extensions::APIPermission::kVideoCapture)) {
 599     GetDefaultDevicesForProfile(profile, false, true, &devices);
 600   }
 601
 602   scoped_ptr<content::MediaStreamUI> ui;
 603   if (!devices.empty()) {
 604     ui = media_stream_capture_indicator_->RegisterMediaStream(
 605         web_contents, devices);
 606   }
 607   callback.Run(
 608     devices,
 609     devices.empty() ? content::MEDIA_DEVICE_INVALID_STATE :
 610                       content::MEDIA_DEVICE_OK,
 611     ui.Pass());
 612 }
 613
 614 void MediaCaptureDevicesDispatcher::ProcessRegularMediaAccessRequest(
 615     content::WebContents* web_contents,
 616     const content::MediaStreamRequest& request,
 617     const content::MediaResponseCallback& callback) {
 618   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 619
 620   RequestsQueue& queue = pending_requests_[web_contents];
 621   queue.push_back(PendingAccessRequest(request, callback));
 622
 623   // If this is the only request then show the infobar.
 624   if (queue.size() == 1)
 625     ProcessQueuedAccessRequest(web_contents);
 626 }
 627
 628 void MediaCaptureDevicesDispatcher::ProcessQueuedAccessRequest(
 629     content::WebContents* web_contents) {
 630   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 631
 632   std::map<content::WebContents*, RequestsQueue>::iterator it =
 633       pending_requests_.find(web_contents);
 634
 635   if (it == pending_requests_.end() || it->second.empty()) {
 636     // Don't do anything if the tab was closed.
 637     return;
 638   }
 639
 640   DCHECK(!it->second.empty());
 641
 642   if (PermissionBubbleManager::Enabled() ||
 643       MediaStreamPermissionBubbleExperimentEnabled()) {
 644     scoped_ptr<MediaStreamDevicesController> controller(
 645         new MediaStreamDevicesController(web_contents,
 646             it->second.front().request,
 647             base::Bind(&MediaCaptureDevicesDispatcher::OnAccessRequestResponse,
 648                        base::Unretained(this), web_contents)));
 649     if (controller->DismissInfoBarAndTakeActionOnSettings())
 650       return;
 651     PermissionBubbleManager* bubble_manager =
 652         PermissionBubbleManager::FromWebContents(web_contents);
 653     if (bubble_manager)
 654       bubble_manager->AddRequest(controller.release());
 655     return;
 656   }
 657
 658   // TODO(gbillock): delete this block and the MediaStreamInfoBarDelegate
 659   // when we've transitioned to bubbles. (crbug/337458)
 660   MediaStreamInfoBarDelegate::Create(
 661       web_contents, it->second.front().request,
 662       base::Bind(&MediaCaptureDevicesDispatcher::OnAccessRequestResponse,
 663                  base::Unretained(this), web_contents));
 664 }
 665
 666 void MediaCaptureDevicesDispatcher::OnAccessRequestResponse(
 667     content::WebContents* web_contents,
 668     const content::MediaStreamDevices& devices,
 669     content::MediaStreamRequestResult result,
 670     scoped_ptr<content::MediaStreamUI> ui) {
 671   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 672
 673   std::map<content::WebContents*, RequestsQueue>::iterator it =
 674       pending_requests_.find(web_contents);
 675   if (it == pending_requests_.end()) {
 676     // WebContents has been destroyed. Don't need to do anything.
 677     return;
 678   }
 679
 680   RequestsQueue& queue(it->second);
 681   if (queue.empty())
 682     return;
 683
 684   content::MediaResponseCallback callback = queue.front().callback;
 685   queue.pop_front();
 686
 687   if (!queue.empty()) {
 688     // Post a task to process next queued request. It has to be done
 689     // asynchronously to make sure that calling infobar is not destroyed until
 690     // after this function returns.
 691     BrowserThread::PostTask(
 692         BrowserThread::UI, FROM_HERE,
 693         base::Bind(&MediaCaptureDevicesDispatcher::ProcessQueuedAccessRequest,
 694                    base::Unretained(this), web_contents));
 695   }
 696
 697   callback.Run(devices, result, ui.Pass());
 698 }
 699
 700 void MediaCaptureDevicesDispatcher::GetDefaultDevicesForProfile(
 701     Profile* profile,
 702     bool audio,
 703     bool video,
 704     content::MediaStreamDevices* devices) {
 705   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 706   DCHECK(audio || video);
 707
 708   PrefService* prefs = profile->GetPrefs();
 709   std::string default_device;
 710   if (audio) {
 711     default_device = prefs->GetString(prefs::kDefaultAudioCaptureDevice);
 712     const content::MediaStreamDevice* device =
 713         GetRequestedAudioDevice(default_device);
 714     if (!device)
 715       device = GetFirstAvailableAudioDevice();
 716     if (device)
 717       devices->push_back(*device);
 718   }
 719
 720   if (video) {
 721     default_device = prefs->GetString(prefs::kDefaultVideoCaptureDevice);
 722     const content::MediaStreamDevice* device =
 723         GetRequestedVideoDevice(default_device);
 724     if (!device)
 725       device = GetFirstAvailableVideoDevice();
 726     if (device)
 727       devices->push_back(*device);
 728   }
 729 }
 730
 731 const content::MediaStreamDevice*
 732 MediaCaptureDevicesDispatcher::GetRequestedAudioDevice(
 733     const std::string& requested_audio_device_id) {
 734   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 735   const content::MediaStreamDevices& audio_devices = GetAudioCaptureDevices();
 736   const content::MediaStreamDevice* const device =
 737       FindDeviceWithId(audio_devices, requested_audio_device_id);
 738   return device;
 739 }
 740
 741 const content::MediaStreamDevice*
 742 MediaCaptureDevicesDispatcher::GetFirstAvailableAudioDevice() {
 743   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 744   const content::MediaStreamDevices& audio_devices = GetAudioCaptureDevices();
 745   if (audio_devices.empty())
 746     return NULL;
 747   return &(*audio_devices.begin());
 748 }
 749
 750 const content::MediaStreamDevice*
 751 MediaCaptureDevicesDispatcher::GetRequestedVideoDevice(
 752     const std::string& requested_video_device_id) {
 753   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 754   const content::MediaStreamDevices& video_devices = GetVideoCaptureDevices();
 755   const content::MediaStreamDevice* const device =
 756       FindDeviceWithId(video_devices, requested_video_device_id);
 757   return device;
 758 }
 759
 760 const content::MediaStreamDevice*
 761 MediaCaptureDevicesDispatcher::GetFirstAvailableVideoDevice() {
 762   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 763   const content::MediaStreamDevices& video_devices = GetVideoCaptureDevices();
 764   if (video_devices.empty())
 765     return NULL;
 766   return &(*video_devices.begin());
 767 }
 768
 769 void MediaCaptureDevicesDispatcher::DisableDeviceEnumerationForTesting() {
 770   is_device_enumeration_disabled_ = true;
 771 }
 772
 773 scoped_refptr<MediaStreamCaptureIndicator>
 774 MediaCaptureDevicesDispatcher::GetMediaStreamCaptureIndicator() {
 775   return media_stream_capture_indicator_;
 776 }
 777
 778 DesktopStreamsRegistry*
 779 MediaCaptureDevicesDispatcher::GetDesktopStreamsRegistry() {
 780   if (!desktop_streams_registry_)
 781     desktop_streams_registry_.reset(new DesktopStreamsRegistry());
 782   return desktop_streams_registry_.get();
 783 }
 784
 785 void MediaCaptureDevicesDispatcher::OnAudioCaptureDevicesChanged() {
 786   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 787   BrowserThread::PostTask(
 788       BrowserThread::UI, FROM_HERE,
 789       base::Bind(
 790           &MediaCaptureDevicesDispatcher::NotifyAudioDevicesChangedOnUIThread,
 791           base::Unretained(this)));
 792 }
 793
 794 void MediaCaptureDevicesDispatcher::OnVideoCaptureDevicesChanged() {
 795   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 796   BrowserThread::PostTask(
 797       BrowserThread::UI, FROM_HERE,
 798       base::Bind(
 799           &MediaCaptureDevicesDispatcher::NotifyVideoDevicesChangedOnUIThread,
 800           base::Unretained(this)));
 801 }
 802
 803 void MediaCaptureDevicesDispatcher::OnMediaRequestStateChanged(
 804     int render_process_id,
 805     int render_view_id,
 806     int page_request_id,
 807     const GURL& security_origin,
 808     const content::MediaStreamDevice& device,
 809     content::MediaRequestState state) {
 810   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 811   BrowserThread::PostTask(
 812       BrowserThread::UI, FROM_HERE,
 813       base::Bind(
 814           &MediaCaptureDevicesDispatcher::UpdateMediaRequestStateOnUIThread,
 815           base::Unretained(this), render_process_id, render_view_id,
 816           page_request_id, security_origin, device, state));
 817 }
 818
 819 void MediaCaptureDevicesDispatcher::OnAudioStreamPlaying(
 820     int render_process_id,
 821     int render_frame_id,
 822     int stream_id,
 823     const ReadPowerAndClipCallback& read_power_callback) {
 824   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 825 #if defined(AUDIO_STREAM_MONITORING)
 826   BrowserThread::PostTask(
 827       BrowserThread::UI,
 828       FROM_HERE,
 829       base::Bind(&StartAudioStreamMonitoringOnUIThread,
 830                  render_process_id,
 831                  render_frame_id,
 832                  stream_id,
 833                  read_power_callback));
 834 #endif
 835 }
 836
 837 void MediaCaptureDevicesDispatcher::OnAudioStreamStopped(
 838     int render_process_id,
 839     int render_frame_id,
 840     int stream_id) {
 841   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 842 #if defined(AUDIO_STREAM_MONITORING)
 843   BrowserThread::PostTask(
 844       BrowserThread::UI,
 845       FROM_HERE,
 846       base::Bind(&StopAudioStreamMonitoringOnUIThread,
 847                  render_process_id,
 848                  render_frame_id,
 849                  stream_id));
 850 #endif
 851 }
 852
 853 void MediaCaptureDevicesDispatcher::OnCreatingAudioStream(
 854     int render_process_id,
 855     int render_frame_id) {
 856   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 857   BrowserThread::PostTask(
 858       BrowserThread::UI, FROM_HERE,
 859       base::Bind(
 860           &MediaCaptureDevicesDispatcher::OnCreatingAudioStreamOnUIThread,
 861           base::Unretained(this), render_process_id, render_frame_id));
 862 }
 863
 864 void MediaCaptureDevicesDispatcher::NotifyAudioDevicesChangedOnUIThread() {
 865   MediaStreamDevices devices = GetAudioCaptureDevices();
 866   FOR_EACH_OBSERVER(Observer, observers_,
 867                     OnUpdateAudioDevices(devices));
 868 }
 869
 870 void MediaCaptureDevicesDispatcher::NotifyVideoDevicesChangedOnUIThread() {
 871   MediaStreamDevices devices = GetVideoCaptureDevices();
 872   FOR_EACH_OBSERVER(Observer, observers_,
 873                     OnUpdateVideoDevices(devices));
 874 }
 875
 876 void MediaCaptureDevicesDispatcher::UpdateMediaRequestStateOnUIThread(
 877     int render_process_id,
 878     int render_view_id,
 879     int page_request_id,
 880     const GURL& security_origin,
 881     const content::MediaStreamDevice& device,
 882     content::MediaRequestState state) {
 883   // Track desktop capture sessions.  Tracking is necessary to avoid unbalanced
 884   // session counts since not all requests will reach MEDIA_REQUEST_STATE_DONE,
 885   // but they will all reach MEDIA_REQUEST_STATE_CLOSING.
 886   if (device.type == content::MEDIA_DESKTOP_VIDEO_CAPTURE) {
 887     if (state == content::MEDIA_REQUEST_STATE_DONE) {
 888       DesktopCaptureSession session = { render_process_id, render_view_id,
 889                                         page_request_id };
 890       desktop_capture_sessions_.push_back(session);
 891     } else if (state == content::MEDIA_REQUEST_STATE_CLOSING) {
 892       for (DesktopCaptureSessions::iterator it =
 893                desktop_capture_sessions_.begin();
 894            it != desktop_capture_sessions_.end();
 895            ++it) {
 896         if (it->render_process_id == render_process_id &&
 897             it->render_view_id == render_view_id &&
 898             it->page_request_id == page_request_id) {
 899           desktop_capture_sessions_.erase(it);
 900           break;
 901         }
 902       }
 903     }
 904   }
 905
 906   // Cancel the request.
 907   if (state == content::MEDIA_REQUEST_STATE_CLOSING) {
 908     bool found = false;
 909     for (RequestsQueues::iterator rqs_it = pending_requests_.begin();
 910          rqs_it != pending_requests_.end(); ++rqs_it) {
 911       RequestsQueue& queue = rqs_it->second;
 912       for (RequestsQueue::iterator it = queue.begin();
 913            it != queue.end(); ++it) {
 914         if (it->request.render_process_id == render_process_id &&
 915             it->request.render_view_id == render_view_id &&
 916             it->request.page_request_id == page_request_id) {
 917           queue.erase(it);
 918           found = true;
 919           break;
 920         }
 921       }
 922       if (found)
 923         break;
 924     }
 925   }
 926
 927 #if defined(OS_CHROMEOS)
 928   if (IsOriginForCasting(security_origin) && IsVideoMediaType(device.type)) {
 929     // Notify ash that casting state has changed.
 930     if (state == content::MEDIA_REQUEST_STATE_DONE) {
 931       ash::Shell::GetInstance()->OnCastingSessionStartedOrStopped(true);
 932     } else if (state == content::MEDIA_REQUEST_STATE_CLOSING) {
 933       ash::Shell::GetInstance()->OnCastingSessionStartedOrStopped(false);
 934     }
 935   }
 936 #endif
 937
 938   FOR_EACH_OBSERVER(Observer, observers_,
 939                     OnRequestUpdate(render_process_id,
 940                                     render_view_id,
 941                                     device,
 942                                     state));
 943 }
 944
 945 void MediaCaptureDevicesDispatcher::OnCreatingAudioStreamOnUIThread(
 946     int render_process_id,
 947     int render_frame_id) {
 948   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 949   FOR_EACH_OBSERVER(Observer, observers_,
 950                     OnCreatingAudioStream(render_process_id, render_frame_id));
 951 #if defined(AUDIO_STREAM_MONITORING)
 952   content::WebContents* const web_contents =
 953       content::WebContents::FromRenderFrameHost(
 954           content::RenderFrameHost::FromID(render_process_id, render_frame_id));
 955   if (web_contents) {
 956     // Note: Calling CreateForWebContents() multiple times is valid (see usage
 957     // info for content::WebContentsUserData).
 958     AudioStreamMonitor::CreateForWebContents(web_contents);
 959   }
 960 #endif
 961 }
 962
 963 bool MediaCaptureDevicesDispatcher::IsDesktopCaptureInProgress() {
 964   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 965   return desktop_capture_sessions_.size() > 0;
 966 }
 967
 968
 969 void MediaCaptureDevicesDispatcher::SetTestAudioCaptureDevices(
 970     const MediaStreamDevices& devices) {
 971   test_audio_devices_ = devices;
 972 }
 973
 974 void MediaCaptureDevicesDispatcher::SetTestVideoCaptureDevices(
 975     const MediaStreamDevices& devices) {
 976   test_video_devices_ = devices;
 977 }