[Mojo Video Capture] Introduce abstraction VideoCaptureSystem

content/browser/renderer_host/media/video_capture_manager.cc

Index: content/browser/renderer_host/media/video_capture_manager.cc
diff --git a/content/browser/renderer_host/media/video_capture_manager.cc b/content/browser/renderer_host/media/video_capture_manager.cc
index 3e38a4d70fd09bedca4a613f34a938122a417b77..45351a50e6c3a42aa4541f18cdae0d862208b944 100644
--- a/content/browser/renderer_host/media/video_capture_manager.cc
+++ b/content/browser/renderer_host/media/video_capture_manager.cc
@@ -58,51 +58,6 @@
 
 namespace {
 
-// Compares two VideoCaptureFormat by checking smallest frame_size area, then
-// by _largest_ frame_rate. Used to order a VideoCaptureFormats vector so that
-// the first entry for a given resolution has the largest frame rate, as needed
-// by the ConsolidateCaptureFormats() method.
-bool IsCaptureFormatSmaller(const media::VideoCaptureFormat& format1,
-                            const media::VideoCaptureFormat& format2) {
-  DCHECK(format1.frame_size.GetCheckedArea().IsValid());
-  DCHECK(format2.frame_size.GetCheckedArea().IsValid());
-  if (format1.frame_size.GetCheckedArea().ValueOrDefault(0) ==
-      format2.frame_size.GetCheckedArea().ValueOrDefault(0)) {
-    return format1.frame_rate > format2.frame_rate;
-  }
-  return format1.frame_size.GetCheckedArea().ValueOrDefault(0) <
-         format2.frame_size.GetCheckedArea().ValueOrDefault(0);
-}
-
-bool IsCaptureFormatSizeEqual(const media::VideoCaptureFormat& format1,
-                              const media::VideoCaptureFormat& format2) {
-  DCHECK(format1.frame_size.GetCheckedArea().IsValid());
-  DCHECK(format2.frame_size.GetCheckedArea().IsValid());
-  return format1.frame_size.GetCheckedArea().ValueOrDefault(0) ==
-         format2.frame_size.GetCheckedArea().ValueOrDefault(0);
-}
-
-// This function receives a list of capture formats, removes duplicated
-// resolutions while keeping the highest frame rate for each, and forcing I420
-// pixel format.
-void ConsolidateCaptureFormats(media::VideoCaptureFormats* formats) {
-  if (formats->empty())
-    return;
-  std::sort(formats->begin(), formats->end(), IsCaptureFormatSmaller);
-  // Due to the ordering imposed, the largest frame_rate is kept while removing
-  // duplicated resolutions.
-  media::VideoCaptureFormats::iterator last =
-      std::unique(formats->begin(), formats->end(), IsCaptureFormatSizeEqual);
-  formats->erase(last, formats->end());
-  // Mark all formats as I420, since this is what the renderer side will get
-  // anyhow: the actual pixel format is decided at the device level.
-  // Don't do this for Y16 format as it is handled separatelly.
-  for (auto& format : *formats) {
-    if (format.pixel_format != media::PIXEL_FORMAT_Y16)
-      format.pixel_format = media::PIXEL_FORMAT_I420;
-  }
-}
-
 // Used for logging capture events.
 // Elements in this enum should not be deleted or rearranged; the only
 // permitted operation is to add new elements before NUM_VIDEO_CAPTURE_EVENT.
@@ -126,19 +81,6 @@ const media::VideoCaptureSessionId kFakeSessionId = -1;
 
 namespace content {
 
-// Bundles a media::VideoCaptureDeviceDescriptor with corresponding supported
-// video formats.
-struct VideoCaptureManager::DeviceInfo {
-  DeviceInfo();
-  DeviceInfo(media::VideoCaptureDeviceDescriptor descriptor);
-  DeviceInfo(const DeviceInfo& other);
-  ~DeviceInfo();
-  DeviceInfo& operator=(const DeviceInfo& other);
-
-  media::VideoCaptureDeviceDescriptor descriptor;
-  media::VideoCaptureFormats supported_formats;
-};
-
 // Class used for queuing request for starting a device.
 class VideoCaptureManager::CaptureDeviceStartRequest {
  public:
@@ -155,20 +97,6 @@ class VideoCaptureManager::CaptureDeviceStartRequest {
   const media::VideoCaptureParams params_;
 };
 
-VideoCaptureManager::DeviceInfo::DeviceInfo() = default;
-
-VideoCaptureManager::DeviceInfo::DeviceInfo(
-    media::VideoCaptureDeviceDescriptor descriptor)
-    : descriptor(descriptor) {}
-
-VideoCaptureManager::DeviceInfo::DeviceInfo(
-    const VideoCaptureManager::DeviceInfo& other) = default;
-
-VideoCaptureManager::DeviceInfo::~DeviceInfo() = default;
-
-VideoCaptureManager::DeviceInfo& VideoCaptureManager::DeviceInfo::operator=(
-    const VideoCaptureManager::DeviceInfo& other) = default;
-
 VideoCaptureManager::CaptureDeviceStartRequest::CaptureDeviceStartRequest(
     VideoCaptureController* controller,
     media::VideoCaptureSessionId session_id,
@@ -176,11 +104,11 @@ VideoCaptureManager::CaptureDeviceStartRequest::CaptureDeviceStartRequest(
     : controller_(controller), session_id_(session_id), params_(params) {}
 
 VideoCaptureManager::VideoCaptureManager(
-    std::unique_ptr<media::VideoCaptureDeviceFactory> factory,
+    std::unique_ptr<media::VideoCaptureSystem> video_capture_system,
     scoped_refptr<base::SingleThreadTaskRunner> device_task_runner)
     : device_task_runner_(std::move(device_task_runner)),
       new_capture_session_id_(1),
-      video_capture_device_factory_(std::move(factory)) {}
+      video_capture_system_(std::move(video_capture_system)) {}
 
 VideoCaptureManager::~VideoCaptureManager() {
   DCHECK(controllers_.empty());
@@ -224,29 +152,17 @@ void VideoCaptureManager::EnumerateDevices(
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DVLOG(1) << "VideoCaptureManager::EnumerateDevices";
 
-  // Bind a callback to ConsolidateDevicesInfoOnDeviceThread() with an argument
-  // for another callback to OnDevicesInfoEnumerated() to be run in the current
-  // loop, i.e. IO loop. Pass a timer for UMA histogram collection.
-  base::Callback<void(std::unique_ptr<VideoCaptureDeviceDescriptors>)>
-      devices_enumerated_callback = base::Bind(
-          &VideoCaptureManager::ConsolidateDevicesInfoOnDeviceThread, this,
-          media::BindToCurrentLoop(base::Bind(
-              &VideoCaptureManager::OnDevicesInfoEnumerated, this,
-              base::Owned(new base::ElapsedTimer()), client_callback)),
-          devices_info_cache_);
-  // OK to use base::Unretained() since we own the VCDFactory and |this| is
-  // bound in |devices_enumerated_callback|.
+  // OK to use base::Unretained(video_capture_system_) since we own the
+  // |video_capture_system_| and |this| is bound in
+  // |devices_enumerated_callback|.
   device_task_runner_->PostTask(
       FROM_HERE,
-      base::Bind(&media::VideoCaptureDeviceFactory::EnumerateDeviceDescriptors,
-                 base::Unretained(video_capture_device_factory_.get()),
-                 devices_enumerated_callback));
-}
-
-const media::VideoCaptureDeviceDescriptor*
-VideoCaptureManager::LookupDeviceDescriptor(const std::string& id) {
-  const DeviceInfo* info = GetDeviceInfoById(id);
-  return info ? (&info->descriptor) : nullptr;
+      base::Bind(&media::VideoCaptureSystem::GetDeviceInfosAsync,
+                 base::Unretained(video_capture_system_.get()),
+                 // Pass a timer for UMA histogram collection.
+                 media::BindToCurrentLoop(base::Bind(
+                     &VideoCaptureManager::OnDeviceInfosReceived, this,
+                     base::Owned(new base::ElapsedTimer()), client_callback))));
 }
 
 int VideoCaptureManager::Open(const MediaStreamDevice& device) {
@@ -337,7 +253,8 @@ void VideoCaptureManager::DoStopDevice(VideoCaptureController* controller) {
     }
   }
 
-  const DeviceInfo* device_info = GetDeviceInfoById(controller->device_id());
+  const media::VideoCaptureDeviceInfo* device_info =
+      GetDeviceInfoById(controller->device_id());
   if (device_info != nullptr) {
     for (auto& observer : capture_observers_)
       observer.OnVideoCaptureStopped(device_info->descriptor.facing);
@@ -368,6 +285,29 @@ void VideoCaptureManager::ProcessDeviceStartRequestQueue() {
   DVLOG(3) << "HandleQueuedStartRequest, Post start to device thread, device = "
            << controller->device_id()
            << " start id = " << controller->serial_id();
+  // The unit test VideoCaptureManagerTest.OpenNotExisting requires us to fail
+  // synchronously if the stream_type is MEDIA_DEVICE_VIDEO_CAPTURE and no
+  // DeviceInfo matching the requested id is present (which is the case when
+  // requesting a device with a bogus id). Note, that since other types of
+  // failure during startup of the device are allowed to be reported
+  // asynchronously, this requirement is questionable.
+  // TODO(chfremer): Check if any production code actually depends on this
+  // requirement. If not, relax the requirement in the test and remove the below
+  // if block.
+  if (controller->stream_type() == MEDIA_DEVICE_VIDEO_CAPTURE) {
+    const media::VideoCaptureDeviceInfo* device_info =
+        GetDeviceInfoById(controller->device_id());
+    if (!device_info) {
+      OnDeviceStartFailed(controller);
+      return;
+    }
+  }
+
+  media::VideoCaptureDeviceInfo* device_info =
+      GetDeviceInfoById(controller->device_id());
+  DCHECK(device_info);
+  for (auto& observer : capture_observers_)
+    observer.OnVideoCaptureStarted(device_info->descriptor.facing);
 
   // The method CreateAndStartDeviceAsync() is going to run asynchronously.
   // Since we may be removing the controller while it is executing, we need to
@@ -384,17 +324,13 @@ void VideoCaptureManager::ProcessDeviceStartRequestQueue() {
                  GetControllerSharedRef(controller)));
 }
 
-void VideoCaptureManager::WillStartDevice(media::VideoFacingMode facing_mode) {
-  for (auto& observer : capture_observers_)
-    observer.OnVideoCaptureStarted(facing_mode);
-}
-
-void VideoCaptureManager::DidStartDevice(VideoCaptureController* controller) {
+void VideoCaptureManager::OnDeviceStarted(VideoCaptureController* controller) {
   DVLOG(3) << __func__;
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(!device_start_request_queue_.empty());
   DCHECK_EQ(controller, device_start_request_queue_.begin()->controller());
   DCHECK(controller);
+
   if (controller->stream_type() == MEDIA_DESKTOP_VIDEO_CAPTURE) {
     const media::VideoCaptureSessionId session_id =
         device_start_request_queue_.front().session_id();
@@ -585,7 +521,7 @@ bool VideoCaptureManager::GetDeviceSupportedFormats(
   DCHECK(supported_formats->empty());
 
   // Return all available formats of the device, regardless its started state.
-  DeviceInfo* existing_device = GetDeviceInfoById(device_id);
+  media::VideoCaptureDeviceInfo* existing_device = GetDeviceInfoById(device_id);
   if (existing_device)
     *supported_formats = existing_device->supported_formats;
   return true;
@@ -743,18 +679,18 @@ void VideoCaptureManager::OnClosed(
     listener.Closed(stream_type, capture_session_id);
 }
 
-void VideoCaptureManager::OnDevicesInfoEnumerated(
+void VideoCaptureManager::OnDeviceInfosReceived(
     base::ElapsedTimer* timer,
     const EnumerationCallback& client_callback,
-    const VideoCaptureManager::DeviceInfos& new_devices_info_cache) {
+    const std::vector<media::VideoCaptureDeviceInfo>& device_infos) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   UMA_HISTOGRAM_TIMES(
       "Media.VideoCaptureManager.GetAvailableDevicesInfoOnDeviceThreadTime",
       timer->Elapsed());
-  devices_info_cache_ = new_devices_info_cache;
+  devices_info_cache_ = device_infos;
 
   // Walk the |devices_info_cache_| and produce a
-  // media::VideoCaptureDeviceDescriptors for return purposes.
+  // media::VideoCaptureDeviceDescriptors for |client_callback|.
   media::VideoCaptureDeviceDescriptors devices;
   std::vector<std::tuple<media::VideoCaptureDeviceDescriptor,
                          media::VideoCaptureFormats>>
@@ -769,40 +705,6 @@ void VideoCaptureManager::OnDevicesInfoEnumerated(
   client_callback.Run(devices);
 }
 
-void VideoCaptureManager::ConsolidateDevicesInfoOnDeviceThread(
-    base::Callback<void(const VideoCaptureManager::DeviceInfos&)>
-        on_devices_enumerated_callback,
-    const VideoCaptureManager::DeviceInfos& old_device_info_cache,
-    std::unique_ptr<VideoCaptureDeviceDescriptors> descriptors_snapshot) {
-  DCHECK(device_task_runner_->BelongsToCurrentThread());
-  // Construct |new_devices_info_cache| with the cached devices that are still
-  // present in the system, and remove their names from |names_snapshot|, so we
-  // keep there the truly new devices.
-  VideoCaptureManager::DeviceInfos new_devices_info_cache;
-  for (const auto& device_info : old_device_info_cache) {
-    for (VideoCaptureDeviceDescriptors::iterator it =
-             descriptors_snapshot->begin();
-         it != descriptors_snapshot->end(); ++it) {
-      if (device_info.descriptor.device_id == it->device_id) {
-        new_devices_info_cache.push_back(device_info);
-        descriptors_snapshot->erase(it);
-        break;
-      }
-    }
-  }
-
-  // Get the device info for the new devices in |names_snapshot|.
-  for (const auto& it : *descriptors_snapshot) {
-    DeviceInfo device_info(it);
-    video_capture_device_factory_->GetSupportedFormats(
-        it, &device_info.supported_formats);
-    ConsolidateCaptureFormats(&device_info.supported_formats);
-    new_devices_info_cache.push_back(device_info);
-  }
-
-  on_devices_enumerated_callback.Run(new_devices_info_cache);
-}
-
 void VideoCaptureManager::DestroyControllerIfNoClients(
     VideoCaptureController* controller) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
@@ -871,7 +773,7 @@ VideoCaptureManager::GetControllerSharedRef(
   return nullptr;
 }
 
-VideoCaptureManager::DeviceInfo* VideoCaptureManager::GetDeviceInfoById(
+media::VideoCaptureDeviceInfo* VideoCaptureManager::GetDeviceInfoById(
     const std::string& id) {
   for (auto& it : devices_info_cache_) {
     if (it.descriptor.device_id == id)
@@ -902,14 +804,14 @@ VideoCaptureController* VideoCaptureManager::GetOrCreateController(
   VideoCaptureController* new_controller = new VideoCaptureController(
       device_info.id, device_info.type, params,
       base::MakeUnique<InProcessBuildableVideoCaptureDevice>(
-          device_task_runner_, video_capture_device_factory_.get()));
+          device_task_runner_, video_capture_system_.get()));
   controllers_.emplace_back(new_controller);
   return new_controller;
 }
 
 base::Optional<CameraCalibration> VideoCaptureManager::GetCameraCalibration(
     const std::string& device_id) {
-  VideoCaptureManager::DeviceInfo* info = GetDeviceInfoById(device_id);
+  media::VideoCaptureDeviceInfo* info = GetDeviceInfoById(device_id);
   if (!info)
     return base::Optional<CameraCalibration>();
   return info->descriptor.camera_calibration;