Begin adding support for tab mirroring via the MediaStream audio/video capturing

content/browser/renderer_host/media/media_stream_manager.cc

Index: content/browser/renderer_host/media/media_stream_manager.cc
diff --git a/content/browser/renderer_host/media/media_stream_manager.cc b/content/browser/renderer_host/media/media_stream_manager.cc
index 3a0f6172374ea7012e2d2acb9582601ce995793c..94b703d59813fa61f8138ba21f122befeb4fc8e5 100644
--- a/content/browser/renderer_host/media/media_stream_manager.cc
+++ b/content/browser/renderer_host/media/media_stream_manager.cc
@@ -47,10 +47,8 @@ static std::string RandomLabel() {
 // Helper to verify if a media stream type is part of options or not.
 static bool Requested(const StreamOptions& options,
                       MediaStreamType stream_type) {
-  return (stream_type == content::MEDIA_STREAM_DEVICE_TYPE_VIDEO_CAPTURE &&
-          options.video) ||
-         (stream_type == content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE &&
-          options.audio);
+  return (options.audio_type == stream_type ||
+          options.video_type == stream_type);
 }
 
 DeviceThread::DeviceThread(const char* name)
@@ -90,12 +88,10 @@ struct MediaStreamManager::DeviceRequest {
 
   DeviceRequest()
       : requester(NULL),
-        state(content::NUM_MEDIA_STREAM_DEVICE_TYPES, STATE_NOT_REQUESTED),
+        state(content::NUM_MEDIA_TYPES, STATE_NOT_REQUESTED),
         type(GENERATE_STREAM),
         render_process_id(-1),
         render_view_id(-1) {
-    options.audio = false;
-    options.video = false;
   }
 
   DeviceRequest(MediaStreamRequester* requester,
@@ -105,7 +101,7 @@ struct MediaStreamManager::DeviceRequest {
                 const GURL& request_security_origin)
       : requester(requester),
         options(request_options),
-        state(content::NUM_MEDIA_STREAM_DEVICE_TYPES, STATE_NOT_REQUESTED),
+        state(content::NUM_MEDIA_TYPES, STATE_NOT_REQUESTED),
         type(GENERATE_STREAM),
         render_process_id(render_process_id),
         render_view_id(render_view_id),
@@ -123,8 +119,7 @@ struct MediaStreamManager::DeviceRequest {
   int render_view_id;
   GURL security_origin;
   std::string requested_device_id;
-  StreamDeviceInfoArray audio_devices;
-  StreamDeviceInfoArray video_devices;
+  StreamDeviceInfoArray devices;
 };
 
 MediaStreamManager::EnumerationCache::EnumerationCache()
@@ -141,15 +136,13 @@ void MediaStreamManager::AlwaysUseFakeDevice() {
   always_use_fake_devices_ = true;
 }
 
-MediaStreamManager::MediaStreamManager(
-    AudioInputDeviceManager* audio_input_device_manager,
-    VideoCaptureManager* video_capture_manager)
+MediaStreamManager::MediaStreamManager(media::AudioManager* audio_manager)
     : ALLOW_THIS_IN_INITIALIZER_LIST(
           device_settings_(new MediaStreamDeviceSettings(this))),
-      audio_input_device_manager_(audio_input_device_manager),
-      video_capture_manager_(video_capture_manager),
+      audio_manager_(audio_manager),
       monitoring_started_(false),
       io_loop_(NULL) {
+  DCHECK(audio_manager_);
   memset(active_enumeration_ref_count_, 0,
          sizeof(active_enumeration_ref_count_));
 }
@@ -162,15 +155,15 @@ MediaStreamManager::~MediaStreamManager() {
 
 VideoCaptureManager* MediaStreamManager::video_capture_manager() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  EnsureDeviceManagersStarted();
   DCHECK(video_capture_manager_);
-  EnsureDeviceThreadAndListener();
   return video_capture_manager_;
 }
 
 AudioInputDeviceManager* MediaStreamManager::audio_input_device_manager() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  EnsureDeviceManagersStarted();
   DCHECK(audio_input_device_manager_);
-  EnsureDeviceThreadAndListener();
   return audio_input_device_manager_;
 }
 
@@ -199,6 +192,45 @@ void MediaStreamManager::GenerateStream(MediaStreamRequester* requester,
                                               security_origin);
 }
 
+void MediaStreamManager::GenerateStreamForDevice(
+    MediaStreamRequester* requester, int render_process_id, int render_view_id,
+    const StreamOptions& options, const std::string& device_id,
+    const GURL& security_origin, std::string* label) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  // Create a new request based on options.
+  AddRequest(DeviceRequest(requester, options,
+                           render_process_id, render_view_id,
+                           security_origin),
+             label);
+  DeviceRequest& request = requests_[*label];
+
+  // Get user confirmation to use the capture device.
+  device_settings_->RequestCaptureDeviceUsage(*label,
+                                              render_process_id,
+                                              render_view_id,
+                                              options,
+                                              security_origin);
+  // TODO(miu): We should ask the device manager whether a device with id
+  // |device_id| actually exists.  Note that no such MediaStreamProvider API for
+  // this currently exists.  Also, we don't have a user-friendly device name for
+  // the infobar UI.
+  if (content::IsAudioMediaType(options.audio_type)) {
+    request.state[options.audio_type] = DeviceRequest::STATE_PENDING_APPROVAL;
+    device_settings_->AvailableDevices(
+        *label, options.audio_type, StreamDeviceInfoArray(
+            1, StreamDeviceInfo(options.audio_type, device_id, device_id,
+                                false)));
+  }
+  if (content::IsVideoMediaType(options.video_type)) {
+    request.state[options.video_type] = DeviceRequest::STATE_PENDING_APPROVAL;
+    device_settings_->AvailableDevices(
+        *label, options.video_type, StreamDeviceInfoArray(
+            1, StreamDeviceInfo(options.video_type, device_id, device_id,
+                                false)));
+  }
+}
+
 void MediaStreamManager::CancelGenerateStream(const std::string& label) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
@@ -206,21 +238,19 @@ void MediaStreamManager::CancelGenerateStream(const std::string& label) {
   if (it != requests_.end()) {
     // The request isn't complete.
     if (!RequestDone(it->second)) {
-      DeviceRequest* request = &(it->second);
-      if (request->state[content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE] ==
-          DeviceRequest::STATE_OPENING) {
-        for (StreamDeviceInfoArray::iterator it =
-             request->audio_devices.begin(); it != request->audio_devices.end();
-             ++it) {
-          audio_input_device_manager()->Close(it->session_id);
+      DeviceRequest& request = it->second;
+      for (int i = content::MEDIA_NO_SERVICE + 1; i < content::NUM_MEDIA_TYPES;
+           ++i) {
+        const MediaStreamType stream_type = static_cast<MediaStreamType>(i);
+        if (request.state[stream_type] != DeviceRequest::STATE_OPENING) {
+          continue;
         }
-      }
-      if (request->state[content::MEDIA_STREAM_DEVICE_TYPE_VIDEO_CAPTURE] ==
-          DeviceRequest::STATE_OPENING) {
-        for (StreamDeviceInfoArray::iterator it =
-             request->video_devices.begin(); it != request->video_devices.end();
-             ++it) {
-          video_capture_manager()->Close(it->session_id);
+        for (StreamDeviceInfoArray::const_iterator device_it =
+                 request.devices.begin();
+             device_it != request.devices.end(); ++device_it) {
+          if (device_it->stream_type == stream_type) {
+            GetDeviceManager(stream_type)->Close(device_it->session_id);
+          }
         }
       }
       requests_.erase(it);
@@ -240,15 +270,10 @@ void MediaStreamManager::StopGeneratedStream(const std::string& label) {
       StopEnumerateDevices(label);
       return;
     }
-    for (StreamDeviceInfoArray::iterator audio_it =
-         it->second.audio_devices.begin();
-         audio_it != it->second.audio_devices.end(); ++audio_it) {
-      audio_input_device_manager()->Close(audio_it->session_id);
-    }
-    for (StreamDeviceInfoArray::iterator video_it =
-         it->second.video_devices.begin();
-         video_it != it->second.video_devices.end(); ++video_it) {
-      video_capture_manager()->Close(video_it->session_id);
+    for (StreamDeviceInfoArray::const_iterator device_it =
+             it->second.devices.begin();
+         device_it != it->second.devices.end(); ++device_it) {
+      GetDeviceManager(device_it->stream_type)->Close(device_it->session_id);
     }
     if (it->second.type == DeviceRequest::GENERATE_STREAM &&
         RequestDone(it->second)) {
@@ -266,18 +291,21 @@ void MediaStreamManager::EnumerateDevices(
     const GURL& security_origin,
     std::string* label) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  DCHECK(type == content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE ||
-         type == content::MEDIA_STREAM_DEVICE_TYPE_VIDEO_CAPTURE);
+  DCHECK(type == content::MEDIA_DEVICE_AUDIO_CAPTURE ||
+         type == content::MEDIA_DEVICE_VIDEO_CAPTURE);
 
   // Create a new request.
   StreamOptions options;
   EnumerationCache* cache = NULL;
-  if (type == content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE) {
-    options.audio = true;
+  if (type == content::MEDIA_DEVICE_AUDIO_CAPTURE) {
+    options.audio_type = type;
     cache = &audio_enumeration_cache_;
-  } else {
-    options.video = true;
+  } else if (type == content::MEDIA_DEVICE_VIDEO_CAPTURE) {
+    options.video_type = type;
     cache = &video_enumeration_cache_;
+  } else {
+    NOTREACHED();
+    return;
   }
 
   DeviceRequest new_request(requester, options,
@@ -289,7 +317,7 @@ void MediaStreamManager::EnumerateDevices(
   if (cache->valid) {
     // Cached device list of this type exists. Just send it out.
     new_request.state[type] = DeviceRequest::STATE_REQUESTED;
-    AddRequest(&new_request, label);
+    AddRequest(new_request, label);
     // Need to post a task since the requester won't have label till
     // this function returns.
     BrowserThread::PostTask(BrowserThread::IO,
@@ -324,13 +352,19 @@ void MediaStreamManager::OpenDevice(
     const GURL& security_origin,
     std::string* label) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  DCHECK(type == content::MEDIA_DEVICE_AUDIO_CAPTURE ||
+         type == content::MEDIA_DEVICE_VIDEO_CAPTURE);
 
   // Create a new request.
   StreamOptions options;
-  if (type == content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE)
-    options.audio = true;
-  else
-    options.video = true;
+  if (content::IsAudioMediaType(type)) {
+    options.audio_type = type;
+  } else if (content::IsVideoMediaType(type)) {
+    options.video_type = type;
+  } else {
+    NOTREACHED();
+    return;
+  }
 
   DeviceRequest new_request(requester, options,
                             render_process_id,
@@ -382,30 +416,24 @@ void MediaStreamManager::StartEnumeration(
     std::string* label) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
-  MediaStreamType stream_type = content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE;
-  if (Requested(new_request->options, stream_type)) {
-    new_request->state[stream_type] = DeviceRequest::STATE_REQUESTED;
-    DCHECK_GE(active_enumeration_ref_count_[stream_type], 0);
-    if (!active_enumeration_ref_count_[stream_type]) {
-      ++active_enumeration_ref_count_[stream_type];
-      GetDeviceManager(stream_type)->EnumerateDevices();
-    }
-  }
-  stream_type = content::MEDIA_STREAM_DEVICE_TYPE_VIDEO_CAPTURE;
-  if (Requested(new_request->options, stream_type)) {
-    new_request->state[stream_type] = DeviceRequest::STATE_REQUESTED;
-    DCHECK_GE(active_enumeration_ref_count_[stream_type], 0);
-    if (!active_enumeration_ref_count_[stream_type]) {
-      ++active_enumeration_ref_count_[stream_type];
-      GetDeviceManager(stream_type)->EnumerateDevices();
+  for (int i = content::MEDIA_NO_SERVICE + 1; i < content::NUM_MEDIA_TYPES;
+       ++i) {
+    const MediaStreamType stream_type = static_cast<MediaStreamType>(i);
+    if (Requested(new_request->options, stream_type)) {
+      new_request->state[stream_type] = DeviceRequest::STATE_REQUESTED;
+      DCHECK_GE(active_enumeration_ref_count_[stream_type], 0);
+      if (active_enumeration_ref_count_[stream_type] == 0) {
+        ++active_enumeration_ref_count_[stream_type];
+        GetDeviceManager(stream_type)->EnumerateDevices();
+      }
     }
   }
 
-  AddRequest(new_request, label);
+  AddRequest(*new_request, label);
 }
 
 void MediaStreamManager::AddRequest(
-    DeviceRequest* new_request,
+    const DeviceRequest& new_request,
     std::string* label) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
@@ -415,12 +443,12 @@ void MediaStreamManager::AddRequest(
     request_label = RandomLabel();
   } while (requests_.find(request_label) != requests_.end());
 
-  requests_.insert(std::make_pair(request_label, *new_request));
+  requests_.insert(std::make_pair(request_label, new_request));
 
   (*label) = request_label;
 }
 
-void MediaStreamManager::EnsureDeviceThreadAndListener() {
+void MediaStreamManager::EnsureDeviceManagersStarted() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   if (device_thread_.get())
     return;
@@ -428,9 +456,14 @@ void MediaStreamManager::EnsureDeviceThreadAndListener() {
   device_thread_.reset(new DeviceThread("MediaStreamDeviceThread"));
   CHECK(device_thread_->Start());
 
+  audio_input_device_manager_ =
+      new media_stream::AudioInputDeviceManager(audio_manager_);
   audio_input_device_manager_->Register(this,
                                         device_thread_->message_loop_proxy());
-  video_capture_manager_->Register(this, device_thread_->message_loop_proxy());
+
+  video_capture_manager_ = new media_stream::VideoCaptureManager();
+  video_capture_manager_->Register(this,
+                                   device_thread_->message_loop_proxy());
 
   // We want to be notified of IO message loop destruction to delete the thread
   // and the device managers.
@@ -448,17 +481,11 @@ void MediaStreamManager::Opened(MediaStreamType stream_type,
   std::string label;
   for (DeviceRequests::iterator request_it = requests_.begin();
        request_it != requests_.end() && request == NULL; ++request_it) {
-    if (stream_type == content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE) {
-      devices = &(request_it->second.audio_devices);
-    } else if (stream_type == content::MEDIA_STREAM_DEVICE_TYPE_VIDEO_CAPTURE) {
-      devices = &(request_it->second.video_devices);
-    } else {
-      NOTREACHED();
-    }
-
+    devices = &(request_it->second.devices);
     for (StreamDeviceInfoArray::iterator device_it = devices->begin();
          device_it != devices->end(); ++device_it) {
-      if (device_it->session_id == capture_session_id) {
+      if (device_it->stream_type == stream_type &&
+          device_it->session_id == capture_session_id) {
         // We've found the request.
         device_it->in_use = true;
         label = request_it->first;
@@ -478,6 +505,9 @@ void MediaStreamManager::Opened(MediaStreamType stream_type,
   // they are.
   for (StreamDeviceInfoArray::iterator device_it = devices->begin();
        device_it != devices->end(); ++device_it) {
+    if (device_it->stream_type != stream_type) {
+      continue;
+    }
     if (device_it->in_use == false) {
       // Wait for more devices to be opened before we're done.
       return;
@@ -492,15 +522,29 @@ void MediaStreamManager::Opened(MediaStreamType stream_type,
 
   switch (request->type) {
     case DeviceRequest::OPEN_DEVICE:
-      request->requester->DeviceOpened(label, (*devices)[0]);
+      request->requester->DeviceOpened(label, devices->front());
       break;
-    case DeviceRequest::GENERATE_STREAM:
-      request->requester->StreamGenerated(label, request->audio_devices,
-                                          request->video_devices);
+    case DeviceRequest::GENERATE_STREAM: {
+      // Partition the array of devices into audio vs video.
+      StreamDeviceInfoArray audio_devices, video_devices;
+      for (StreamDeviceInfoArray::const_iterator device_it = devices->begin();
+           device_it != devices->end(); ++device_it) {
+        if (content::IsAudioMediaType(device_it->stream_type)) {
+          audio_devices.push_back(*device_it);
+        } else if (content::IsVideoMediaType(device_it->stream_type)) {
+          video_devices.push_back(*device_it);
+        } else {
+          NOTREACHED();
+        }
+      }
+
+      request->requester->StreamGenerated(label, audio_devices, video_devices);
       NotifyObserverDevicesOpened(request);
       break;
+    }
     default:
       NOTREACHED();
+      break;
   }
 }
 
@@ -513,11 +557,11 @@ void MediaStreamManager::DevicesEnumerated(
     MediaStreamType stream_type, const StreamDeviceInfoArray& devices) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
-  // Only cache device list when there is EnumerateDevices request, since
+  // Only cache the device list when there is an EnumerateDevices request, since
   // other requests don't turn on device monitoring.
   bool need_update_clients = false;
   EnumerationCache* cache =
-      (stream_type == content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE ?
+      (stream_type == content::MEDIA_DEVICE_AUDIO_CAPTURE ?
        &audio_enumeration_cache_ : &video_enumeration_cache_);
   if (HasEnumerationRequest(stream_type) &&
       (!cache->valid ||
@@ -552,8 +596,9 @@ void MediaStreamManager::DevicesEnumerated(
           request.requester->DevicesEnumerated(*it, devices);
         break;
       case DeviceRequest::OPEN_DEVICE:
+        DCHECK(!request.requested_device_id.empty());
         for (StreamDeviceInfoArray::const_iterator device_it = devices.begin();
-             device_it != devices.end(); device_it++) {
+             device_it != devices.end(); ++device_it) {
           if (request.requested_device_id == device_it->device_id) {
             StreamDeviceInfo device = *device_it;
             device.in_use = false;
@@ -561,16 +606,14 @@ void MediaStreamManager::DevicesEnumerated(
                 GetDeviceManager(device_it->stream_type)->Open(device);
             request.state[device_it->stream_type] =
                 DeviceRequest::STATE_OPENING;
-            if (stream_type == content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE)
-              request.audio_devices.push_back(device);
-            else
-              request.video_devices.push_back(device);
+            request.devices.push_back(device);
             break;
           }
         }
         break;
       default:
         device_settings_->AvailableDevices(*it, stream_type, devices);
+        break;
     }
   }
   label_list.clear();
@@ -583,52 +626,61 @@ void MediaStreamManager::Error(MediaStreamType stream_type,
                                MediaStreamProviderError error) {
   // Find the device for the error call.
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
   for (DeviceRequests::iterator it = requests_.begin(); it != requests_.end();
        ++it) {
-    StreamDeviceInfoArray* devices = NULL;
-    if (stream_type == content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE) {
-      devices = &(it->second.audio_devices);
-    } else if (stream_type == content::MEDIA_STREAM_DEVICE_TYPE_VIDEO_CAPTURE) {
-      devices = &(it->second.video_devices);
-    } else {
-      NOTREACHED();
-    }
-
-    int device_idx = 0;
-    for (StreamDeviceInfoArray::iterator device_it = devices->begin();
-         device_it != devices->end(); ++device_it, ++device_idx) {
-      if (device_it->session_id == capture_session_id) {
-        // We've found the failing device. Find the error case:
-        if (it->second.state[stream_type] == DeviceRequest::STATE_DONE) {
-          // 1. Already opened -> signal device failure and close device.
-          //    Use device_idx to signal which of the devices encountered an
-          //    error.
-          if (stream_type == content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE) {
-            it->second.requester->AudioDeviceFailed(it->first, device_idx);
-          } else if (stream_type ==
-                     content::MEDIA_STREAM_DEVICE_TYPE_VIDEO_CAPTURE) {
-            it->second.requester->VideoDeviceFailed(it->first, device_idx);
-          }
-          GetDeviceManager(stream_type)->Close(capture_session_id);
-          // We don't erase the devices here so that we can update the UI
-          // properly in StopGeneratedStream().
-          it->second.state[stream_type] = DeviceRequest::STATE_ERROR;
+    StreamDeviceInfoArray& devices = it->second.devices;
+
+    // TODO(miu): BUG.  It's possible for the audio (or video) device array in
+    // the "requester" to become out-of-sync with the order of devices we have
+    // here.  See http://crbug.com/147650
+    int audio_device_idx = -1;
+    int video_device_idx = -1;
+    for (StreamDeviceInfoArray::iterator device_it = devices.begin();
+         device_it != devices.end(); ++device_it) {
+      if (content::IsAudioMediaType(device_it->stream_type)) {
+        ++audio_device_idx;
+      } else if (content::IsVideoMediaType(device_it->stream_type)) {
+        ++video_device_idx;
+      } else {
+        NOTREACHED();
+        continue;
+      }
+      if (device_it->stream_type != stream_type ||
+          device_it->session_id != capture_session_id) {
+        continue;
+      }
+      // We've found the failing device. Find the error case:
+      if (it->second.state[stream_type] == DeviceRequest::STATE_DONE) {
+        // 1. Already opened -> signal device failure and close device.
+        //    Use device_idx to signal which of the devices encountered an
+        //    error.
+        if (content::IsAudioMediaType(stream_type)) {
+          it->second.requester->AudioDeviceFailed(it->first, audio_device_idx);
+        } else if (content::IsVideoMediaType(stream_type)) {
+          it->second.requester->VideoDeviceFailed(it->first, video_device_idx);
         } else {
-          // Request is not done, devices are not opened in this case.
-          if ((it->second.audio_devices.size() +
-               it->second.video_devices.size()) <= 1) {
-            // 2. Device not opened and no other devices for this request ->
-            //    signal stream error and remove the request.
-            it->second.requester->StreamGenerationFailed(it->first);
-            requests_.erase(it);
-          } else {
-            // 3. Not opened but other devices exists for this request -> remove
-            //    device from list, but don't signal an error.
-            devices->erase(device_it);
-          }
+          NOTREACHED();
+          return;
+        }
+        GetDeviceManager(stream_type)->Close(capture_session_id);
+        // We don't erase the devices here so that we can update the UI
+        // properly in StopGeneratedStream().
+        it->second.state[stream_type] = DeviceRequest::STATE_ERROR;
+      } else {
+        // Request is not done, devices are not opened in this case.
+        if (devices.size() <= 1) {
+          // 2. Device not opened and no other devices for this request ->
+          //    signal stream error and remove the request.
+          it->second.requester->StreamGenerationFailed(it->first);
+          requests_.erase(it);
+        } else {
+          // 3. Not opened but other devices exists for this request -> remove
+          //    device from list, but don't signal an error.
+          devices.erase(device_it);  // NOTE: This invalidates device_it!
         }
-        return;
       }
+      return;
     }
   }
 }
@@ -637,53 +689,50 @@ void MediaStreamManager::DevicesAccepted(const std::string& label,
                                          const StreamDeviceInfoArray& devices) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DeviceRequests::iterator request_it = requests_.find(label);
-  if (request_it != requests_.end()) {
-    if (devices.empty()) {
-      // No available devices or user didn't accept device usage.
-      request_it->second.requester->StreamGenerationFailed(request_it->first);
-      requests_.erase(request_it);
-      return;
-    }
+  if (request_it == requests_.end()) {
+    return;
+  }
 
-    // Loop through all device types for this request.
-    for (StreamDeviceInfoArray::const_iterator device_it = devices.begin();
-         device_it != devices.end(); ++device_it) {
-      StreamDeviceInfo device_info = *device_it;
-
-      // Set in_use to false to be able to track if this device has been
-      // opened. in_use might be true if the device type can be used in more
-      // than one session.
-      DCHECK_EQ(request_it->second.state[device_it->stream_type],
-                DeviceRequest::STATE_PENDING_APPROVAL);
-      device_info.in_use = false;
-      device_info.session_id =
-          GetDeviceManager(device_info.stream_type)->Open(device_info);
-      request_it->second.state[device_it->stream_type] =
-          DeviceRequest::STATE_OPENING;
-      if (device_info.stream_type ==
-          content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE) {
-        request_it->second.audio_devices.push_back(device_info);
-      } else if (device_info.stream_type ==
-                 content::MEDIA_STREAM_DEVICE_TYPE_VIDEO_CAPTURE) {
-        request_it->second.video_devices.push_back(device_info);
-      } else {
-        NOTREACHED();
-      }
-    }
-    // Check if we received all stream types requested.
-    MediaStreamType stream_type =
-        content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE;
-    if (Requested(request_it->second.options, stream_type) &&
-        request_it->second.audio_devices.size() == 0) {
-      request_it->second.state[stream_type] = DeviceRequest::STATE_ERROR;
-    }
-    stream_type = content::MEDIA_STREAM_DEVICE_TYPE_VIDEO_CAPTURE;
-    if (Requested(request_it->second.options, stream_type) &&
-        request_it->second.video_devices.size() == 0) {
-      request_it->second.state[stream_type] = DeviceRequest::STATE_ERROR;
-    }
+  DeviceRequest& request = request_it->second;
+
+  if (devices.empty()) {
+    // No available devices or user didn't accept device usage.
+    request.requester->StreamGenerationFailed(request_it->first);
+    requests_.erase(request_it);
     return;
   }
+
+  // Process all newly-accepted devices for this request.
+  bool found_audio = false, found_video = false;
+  for (StreamDeviceInfoArray::const_iterator device_it = devices.begin();
+       device_it != devices.end(); ++device_it) {
+    StreamDeviceInfo device_info = *device_it;  // Make a copy.
+
+    // Set in_use to false to be able to track if this device has been
+    // opened. in_use might be true if the device type can be used in more
+    // than one session.
+    DCHECK_EQ(request.state[device_it->stream_type],
+              DeviceRequest::STATE_PENDING_APPROVAL);
+    device_info.in_use = false;
+    device_info.session_id =
+        GetDeviceManager(device_info.stream_type)->Open(device_info);
+    request.state[device_it->stream_type] = DeviceRequest::STATE_OPENING;
+    request.devices.push_back(device_info);
+
+    if (device_info.stream_type == request.options.audio_type) {
+      found_audio = true;
+    } else if (device_info.stream_type == request.options.video_type) {
+      found_video = true;
+    }
+  }
+
+  // Check whether we've received all stream types requested.
+  if (!found_audio && content::IsAudioMediaType(request.options.audio_type)) {
+    request.state[request.options.audio_type] = DeviceRequest::STATE_ERROR;
+  }
+  if (!found_video && content::IsVideoMediaType(request.options.video_type)) {
+    request.state[request.options.video_type] = DeviceRequest::STATE_ERROR;
+  }
 }
 
 void MediaStreamManager::SettingsError(const std::string& label) {
@@ -750,68 +799,52 @@ void MediaStreamManager::NotifyObserverDevicesClosed(DeviceRequest* request) {
 
 void MediaStreamManager::DevicesFromRequest(
     DeviceRequest* request, content::MediaStreamDevices* devices) {
-  StreamDeviceInfoArray::const_iterator it = request->audio_devices.begin();
-  for (; it != request->audio_devices.end(); ++it) {
-    devices->push_back(
-        content::MediaStreamDevice(
-            content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE,
-            it->device_id,
-            it->name));
-  }
-  for (it = request->video_devices.begin(); it != request->video_devices.end();
-       ++it) {
-    devices->push_back(
-        content::MediaStreamDevice(
-            content::MEDIA_STREAM_DEVICE_TYPE_VIDEO_CAPTURE,
-            it->device_id,
-            it->name));
+  for (StreamDeviceInfoArray::const_iterator it = request->devices.begin();
+       it != request->devices.end(); ++it) {
+    devices->push_back(content::MediaStreamDevice(
+        it->stream_type, it->device_id, it->name));
   }
 }
 
 bool MediaStreamManager::RequestDone(const DeviceRequest& request) const {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  // Check if all devices are opened.
-  MediaStreamType stream_type = content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE;
-  if (Requested(request.options, stream_type)) {
-    if (request.state[stream_type] != DeviceRequest::STATE_DONE &&
-        request.state[stream_type] != DeviceRequest::STATE_ERROR) {
-      return false;
-    }
 
-    for (StreamDeviceInfoArray::const_iterator it =
-         request.audio_devices.begin(); it != request.audio_devices.end();
-         ++it) {
-      if (it->in_use == false) {
-        return false;
-      }
-    }
+  const bool requested_audio =
+      content::IsAudioMediaType(request.options.audio_type);
+  const bool requested_video =
+      content::IsVideoMediaType(request.options.video_type);
+
+  const bool audio_done =
+      !requested_audio ||
+      request.state[request.options.audio_type] == DeviceRequest::STATE_DONE ||
+      request.state[request.options.audio_type] == DeviceRequest::STATE_ERROR;
+  if (!audio_done) {
+    return false;
   }
 
-  stream_type = content::MEDIA_STREAM_DEVICE_TYPE_VIDEO_CAPTURE;
-  if (Requested(request.options, stream_type)) {
-    if (request.state[stream_type] != DeviceRequest::STATE_DONE &&
-        request.state[stream_type] != DeviceRequest::STATE_ERROR) {
-      return false;
-    }
+  const bool video_done =
+      !requested_video ||
+      request.state[request.options.video_type] == DeviceRequest::STATE_DONE ||
+      request.state[request.options.video_type] == DeviceRequest::STATE_ERROR;
+  if (!video_done) {
+    return false;
+  }
 
-    for (StreamDeviceInfoArray::const_iterator it =
-         request.video_devices.begin(); it != request.video_devices.end();
-         ++it) {
-      if (it->in_use == false) {
-        return false;
-      }
+  for (StreamDeviceInfoArray::const_iterator it = request.devices.begin();
+       it != request.devices.end(); ++it) {
+    if (it->in_use == false) {
+      return false;
     }
   }
 
   return true;
 }
 
-// Called to get media capture device manager of specified type.
 MediaStreamProvider* MediaStreamManager::GetDeviceManager(
     MediaStreamType stream_type) {
-  if (stream_type == content::MEDIA_STREAM_DEVICE_TYPE_VIDEO_CAPTURE) {
+  if (content::IsVideoMediaType(stream_type)) {
     return video_capture_manager();
-  } else if (stream_type == content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE) {
+  } else if (content::IsAudioMediaType(stream_type)) {
     return audio_input_device_manager();
   }
   NOTREACHED();
@@ -821,13 +854,17 @@ MediaStreamProvider* MediaStreamManager::GetDeviceManager(
 void MediaStreamManager::OnDevicesChanged(
     base::SystemMonitor::DeviceType device_type) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  // NOTE: This method is only called in response to physical audio/video device
+  // changes (from the operating system).
+
   MediaStreamType stream_type;
   EnumerationCache* cache;
   if (device_type == base::SystemMonitor::DEVTYPE_AUDIO_CAPTURE) {
-    stream_type = content::MEDIA_STREAM_DEVICE_TYPE_AUDIO_CAPTURE;
+    stream_type = content::MEDIA_DEVICE_AUDIO_CAPTURE;
     cache = &audio_enumeration_cache_;
   } else if (device_type == base::SystemMonitor::DEVTYPE_VIDEO_CAPTURE) {
-    stream_type = content::MEDIA_STREAM_DEVICE_TYPE_VIDEO_CAPTURE;
+    stream_type = content::MEDIA_DEVICE_VIDEO_CAPTURE;
     cache = &video_enumeration_cache_;
   } else {
     return;  // Uninteresting device change.