[Mojo Video Capture] Decouple VCController from VCBufferPool and VCDeviceClient

content/browser/renderer_host/media/video_capture_manager.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/media/video_capture_manager.h"
 
 #include <algorithm>
 #include <set>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/task_runner_util.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
 #include "content/browser/media/capture/desktop_capture_device_uma_types.h"
 #include "content/browser/media/capture/web_contents_video_capture_device.h"
 #include "content/browser/media/media_internals.h"
 #include "content/browser/renderer_host/media/video_capture_controller.h"
 #include "content/browser/renderer_host/media/video_capture_controller_event_handler.h"
+#include "content/browser/renderer_host/media/video_capture_gpu_jpeg_decoder.h"
+#include "content/browser/renderer_host/media/video_frame_receiver_on_io_thread.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/desktop_media_id.h"
 #include "content/public/common/media_stream_request.h"
 #include "media/base/bind_to_current_loop.h"
 #include "media/base/media_switches.h"
+#include "media/capture/video/video_capture_buffer_pool_impl.h"
+#include "media/capture/video/video_capture_buffer_tracker_factory_impl.h"
 #include "media/capture/video/video_capture_device.h"
+#include "media/capture/video/video_capture_device_client.h"
 #include "media/capture/video/video_capture_device_factory.h"
 
 #if defined(ENABLE_SCREEN_CAPTURE) && !defined(OS_ANDROID)
 #include "content/browser/media/capture/desktop_capture_device.h"
 #if defined(USE_AURA)
 #include "content/browser/media/capture/desktop_capture_device_aura.h"
 #endif
 #endif
 
 #if defined(ENABLE_SCREEN_CAPTURE) && defined(OS_ANDROID)
@@ skipping 61 matching lines @@
   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;
   }
 }
 
-// The maximum number of buffers in the capture pipeline. See
-// VideoCaptureController ctor comments for more details.
+// The maximum number of video frame buffers in-flight at any one time. This
+// value should be based on the logical capacity of the capture pipeline, and
+// not on hardware performance.  For example, tab capture requires more buffers
+// than webcam capture because the pipeline is longer (it includes read-backs
+// pending in the GPU pipeline).
 const int kMaxNumberOfBuffers = 3;
 // TODO(miu): The value for tab capture should be determined programmatically.
 // http://crbug.com/460318
 const int kMaxNumberOfBuffersForTabCapture = 10;
 
 // 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.
 enum VideoCaptureEvent {
   VIDEO_CAPTURE_START_CAPTURE = 0,
   VIDEO_CAPTURE_STOP_CAPTURE_OK = 1,
   VIDEO_CAPTURE_STOP_CAPTURE_DUE_TO_ERROR = 2,
   VIDEO_CAPTURE_STOP_CAPTURE_OK_NO_FRAMES_PRODUCED_BY_DEVICE = 3,
   VIDEO_CAPTURE_STOP_CAPTURE_OK_NO_FRAMES_PRODUCED_BY_DESKTOP_OR_TAB = 4,
   NUM_VIDEO_CAPTURE_EVENT
 };
 
 void LogVideoCaptureEvent(VideoCaptureEvent event) {
   UMA_HISTOGRAM_ENUMERATION("Media.VideoCaptureManager.Event",
                             event,
                             NUM_VIDEO_CAPTURE_EVENT);
 }
 
 // Counter used for identifying a DeviceRequest to start a capture device.
 static int g_device_start_id = 0;
 
 const media::VideoCaptureSessionId kFakeSessionId = -1;
 
+std::unique_ptr<media::VideoCaptureJpegDecoder> CreateGpuJpegDecoder(
+    const media::VideoCaptureJpegDecoder::DecodeDoneCB& decode_done_cb) {
+  return base::MakeUnique<content::VideoCaptureGpuJpegDecoder>(decode_done_cb);
+}
+
 }  // namespace
 
 namespace content {
 
 // Instances of this struct go through 3 different phases during their lifetime.
 // Phase 1: When first created (in GetOrCreateDeviceEntry()), this consists of
 // only a controller. Clients can already connect to the controller, but there
 // is no device present.
 // Phase 2: When a request to "start" the entry comes in (via
 // HandleQueuedStartRequest()), a VideoCaptureDevice::Client is created
-// via video_capture_controller()->NewDeviceClient() and is used to schedule the
+// via CreateDeviceClient() and is used to schedule the
 // creation and start of a VideoCaptureDevice on the Device Thread.
 // Phase 3: As soon as the creation of the VideoCaptureDevice is complete, this
 // newly created VideoCaptureDevice instance is connected to the
 // VideoCaptureController via SetConsumerFeedbackObserver().
-class VideoCaptureManager::DeviceEntry {
+struct VideoCaptureManager::DeviceEntry {
  public:
   DeviceEntry(MediaStreamType stream_type,
               const std::string& id,
               std::unique_ptr<VideoCaptureController> controller,
               const media::VideoCaptureParams& params);
   ~DeviceEntry();
+  std::unique_ptr<media::VideoCaptureDevice::Client> CreateDeviceClient();
+  std::unique_ptr<media::FrameBufferHost> CreateFrameBufferHost();
 
   const int serial_id;
   const MediaStreamType stream_type;
   const std::string id;
   const media::VideoCaptureParams parameters;
-
-  VideoCaptureController* video_capture_controller() const;
-  media::VideoCaptureDevice* video_capture_device() const;
-
-  void SetVideoCaptureDevice(std::unique_ptr<VideoCaptureDevice> device);
-  std::unique_ptr<VideoCaptureDevice> ReleaseVideoCaptureDevice();
-
- private:
-  const std::unique_ptr<VideoCaptureController> video_capture_controller_;
-
-  std::unique_ptr<VideoCaptureDevice> video_capture_device_;
-
-  base::ThreadChecker thread_checker_;
+  const std::unique_ptr<VideoCaptureController> video_capture_controller;
+  scoped_refptr<media::VideoCaptureBufferPool> buffer_pool;
+  std::unique_ptr<media::VideoCaptureDevice> video_capture_device;
 };
 
 // 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 BufferPoolFrameBufferHost : public media::FrameBufferHost {
+ public:
+  BufferPoolFrameBufferHost(
+      scoped_refptr<media::VideoCaptureBufferPool> buffer_pool)
+      : buffer_pool_(std::move(buffer_pool)) {}
+
+  void SetBufferHold(int buffer_id) override {
+    buffer_pool_->HoldForConsumers(buffer_id, 1);
+  }
+
+  void ReleaseBufferHold(int buffer_id) override {
+    buffer_pool_->RelinquishConsumerHold(buffer_id, 1);
+  }
+
+  mojo::ScopedSharedBufferHandle GetHandleForTransit(int buffer_id) override {
+    return buffer_pool_->GetHandleForTransit(buffer_id);
+  }
+
+ private:
+  scoped_refptr<media::VideoCaptureBufferPool> buffer_pool_;

[mcasas, 2016/12/06 20:02:24]

media::FrameBufferHost (and BufferPoolFrameBufferHost) 
are not ref counted whereas media::VideoCaptureBufferPool
is.  This forces you to use naked pointers in VCC::BufferState,
is it because you envision the mojo-based interface to not
be ref-counted...?

[chfremer, 2016/12/06 21:07:41]

The reason is that I am trying to avoid shared ownership in 
favor of clear ownership rules. Since shared ownership is not 
needed here, I opted for one unique_ptr<> for the owner and 
raw pointers for non-owning users.

+};
+
 // Class used for queuing request for starting a device.
 class VideoCaptureManager::CaptureDeviceStartRequest {
  public:
   CaptureDeviceStartRequest(int serial_id,
                             media::VideoCaptureSessionId session_id,
                             const media::VideoCaptureParams& params);
   int serial_id() const { return serial_id_; }
   media::VideoCaptureSessionId session_id() const { return session_id_; }
   media::VideoCaptureParams params() const { return params_; }
 
@@ skipping 13 matching lines @@
 
 VideoCaptureManager::DeviceEntry::DeviceEntry(
     MediaStreamType stream_type,
     const std::string& id,
     std::unique_ptr<VideoCaptureController> controller,
     const media::VideoCaptureParams& params)
     : serial_id(g_device_start_id++),
       stream_type(stream_type),
       id(id),
       parameters(params),
-      video_capture_controller_(std::move(controller)) {}
+      video_capture_controller(std::move(controller)) {}
 
 VideoCaptureManager::DeviceEntry::~DeviceEntry() {
-  DCHECK(thread_checker_.CalledOnValidThread());
   // DCHECK that this DeviceEntry does not still own a
   // media::VideoCaptureDevice. media::VideoCaptureDevice must be deleted on
   // the device thread.
-  DCHECK(video_capture_device_ == nullptr);
+  DCHECK(video_capture_device == nullptr);
 }
 
-void VideoCaptureManager::DeviceEntry::SetVideoCaptureDevice(
-    std::unique_ptr<VideoCaptureDevice> device) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  video_capture_device_.swap(device);
+std::unique_ptr<media::VideoCaptureDevice::Client>
+VideoCaptureManager::DeviceEntry::CreateDeviceClient() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  const int max_buffers = stream_type == MEDIA_TAB_VIDEO_CAPTURE
+                              ? kMaxNumberOfBuffersForTabCapture
+                              : kMaxNumberOfBuffers;
+  buffer_pool = new media::VideoCaptureBufferPoolImpl(
+      base::MakeUnique<media::VideoCaptureBufferTrackerFactoryImpl>(),
+      max_buffers);
+
+  return base::MakeUnique<media::VideoCaptureDeviceClient>(
+      base::MakeUnique<VideoFrameReceiverOnIOThread>(
+          video_capture_controller->GetWeakPtrForIOThread()),
+      buffer_pool,
+      base::Bind(
+          &CreateGpuJpegDecoder,
+          base::Bind(&media::VideoFrameReceiver::OnIncomingCapturedVideoFrame,
+                     video_capture_controller->GetWeakPtrForIOThread())));
 }
 
-std::unique_ptr<media::VideoCaptureDevice>
-VideoCaptureManager::DeviceEntry::ReleaseVideoCaptureDevice() {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  return std::move(video_capture_device_);
-}
-
-VideoCaptureController*
-VideoCaptureManager::DeviceEntry::video_capture_controller() const {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  return video_capture_controller_.get();
-}
-
-media::VideoCaptureDevice*
-VideoCaptureManager::DeviceEntry::video_capture_device() const {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  return video_capture_device_.get();
+std::unique_ptr<media::FrameBufferHost>
+VideoCaptureManager::DeviceEntry::CreateFrameBufferHost() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DCHECK(buffer_pool);
+  return base::MakeUnique<BufferPoolFrameBufferHost>(buffer_pool);
 }
 
 VideoCaptureManager::DeviceInfo::DeviceInfo() = default;
 
 VideoCaptureManager::DeviceInfo::DeviceInfo(
     media::VideoCaptureDeviceDescriptor descriptor)
     : descriptor(descriptor) {}
 
 VideoCaptureManager::DeviceInfo::DeviceInfo(
     const VideoCaptureManager::DeviceInfo& other) = default;
@@ skipping 101 matching lines @@
   if (session_it == sessions_.end()) {
     NOTREACHED();
     return;
   }
 
   DeviceEntry* const existing_device =
       GetDeviceEntryByTypeAndId(session_it->second.type, session_it->second.id);
   if (existing_device) {
     // Remove any client that is still using the session. This is safe to call
     // even if there are no clients using the session.
-    existing_device->video_capture_controller()
-        ->StopSession(capture_session_id);
+    existing_device->video_capture_controller->StopSession(capture_session_id);
 
     // StopSession() may have removed the last client, so we might need to
     // close the device.
     DestroyDeviceEntryIfNoClients(existing_device);
   }
 
   // Notify listeners asynchronously, and forget the session.
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, base::Bind(&VideoCaptureManager::OnClosed, this,
                             session_it->second.type, capture_session_id));
@@ skipping 27 matching lines @@
     if (request->serial_id() == entry->serial_id) {
       request->set_abort_start();
       DVLOG(3) << "DoStopDevice, aborting start request for device "
                << entry->id << " serial_id = " << entry->serial_id;
       return;
     }
   }
 
   DVLOG(3) << "DoStopDevice. Send stop request for device = " << entry->id
            << " serial_id = " << entry->serial_id << ".";
-  entry->video_capture_controller()->OnLog(
+  entry->video_capture_controller->OnLog(
       base::StringPrintf("Stopping device: id: %s", entry->id.c_str()));
-  entry->video_capture_controller()->SetConsumerFeedbackObserver(nullptr);
+  entry->video_capture_controller->SetConsumerFeedbackObserver(nullptr);
+  entry->video_capture_controller->SetFrameBufferHost(nullptr);
 
   // |entry->video_capture_device| can be null if creating the device has
   // failed.
-  if (entry->video_capture_device()) {
+  if (entry->video_capture_device) {
     device_task_runner_->PostTask(
         FROM_HERE,
         base::Bind(&VideoCaptureManager::DoStopDeviceOnDeviceThread, this,
-                   base::Passed(entry->ReleaseVideoCaptureDevice())));
+                   base::Passed(&entry->video_capture_device)));

[mcasas, 2016/12/06 20:02:24]

std::move(entry->video_capture_device())

[chfremer, 2016/12/06 21:07:41]

Hmm, I don't fully understand the documentation of base::Bind, but when trying
to use std::move() here, I get the following compile error:

../../base/bind_internal.h:214:31: error: call to deleted constructor of
'std::unique_ptr<media::VideoCaptureDevice,
std::default_delete<media::VideoCaptureDevice> >'
    return (receiver.*method)(std::forward<RunArgs>(args)...);
                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~

   }
 }
 
 void VideoCaptureManager::HandleQueuedStartRequest() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   // Remove all start requests that have been aborted.
   while (device_start_queue_.begin() != device_start_queue_.end() &&
       device_start_queue_.begin()->abort_start()) {
     device_start_queue_.pop_front();
   }
   DeviceStartQueue::iterator request = device_start_queue_.begin();
   if (request == device_start_queue_.end())
     return;
 
   const int serial_id = request->serial_id();
   DeviceEntry* const entry = GetDeviceEntryBySerialId(serial_id);
   DCHECK(entry);
 
   DVLOG(3) << "HandleQueuedStartRequest, Post start to device thread, device = "
            << entry->id << " start id = " << entry->serial_id;
 
+  std::unique_ptr<media::VideoCaptureDevice::Client> device_client =
+      entry->CreateDeviceClient();
+  std::unique_ptr<media::FrameBufferHost> frame_buffer_host =
+      entry->CreateFrameBufferHost();
+
   base::Callback<std::unique_ptr<VideoCaptureDevice>(void)>
       start_capture_function;
 
   switch (entry->stream_type) {
     case MEDIA_DEVICE_VIDEO_CAPTURE: {
       // We look up the device id from the renderer in our local enumeration
       // since the renderer does not have all the information that might be
       // held in the browser-side VideoCaptureDevice::Name structure.
       const DeviceInfo* found = GetDeviceInfoById(entry->id);
       if (found) {
-        entry->video_capture_controller()->OnLog(
+        entry->video_capture_controller->OnLog(
             base::StringPrintf("Starting device: id: %s, name: %s, api: %s",
                                found->descriptor.device_id.c_str(),
                                found->descriptor.GetNameAndModel().c_str(),
                                found->descriptor.GetCaptureApiTypeString()));
 
-        start_capture_function = base::Bind(
-            &VideoCaptureManager::DoStartDeviceCaptureOnDeviceThread, this,
-            found->descriptor, request->params(),
-            base::Passed(entry->video_capture_controller()->NewDeviceClient()));
+        start_capture_function =
+            base::Bind(&VideoCaptureManager::DoStartDeviceCaptureOnDeviceThread,
+                       this, found->descriptor, request->params(),
+                       base::Passed(std::move(device_client)));
       } else {
         // Errors from DoStartDeviceCaptureOnDeviceThread go via
         // VideoCaptureDeviceClient::OnError, which needs some thread
         // dancing to get errors processed on the IO thread. But since
         // we're on that thread, we call VideoCaptureController
         // methods directly.
         const std::string log_message = base::StringPrintf(
             "Error on %s:%d: device %s unknown. Maybe recently disconnected?",
             __FILE__, __LINE__, entry->id.c_str());
         DLOG(ERROR) << log_message;
-        entry->video_capture_controller()->OnLog(log_message);
-        entry->video_capture_controller()->OnError();
+        entry->video_capture_controller->OnLog(log_message);
+        entry->video_capture_controller->OnError();
         // Drop the failed start request.
         device_start_queue_.pop_front();
 
         return;
       }
       break;
     }
     case MEDIA_TAB_VIDEO_CAPTURE:
       start_capture_function = base::Bind(
           &VideoCaptureManager::DoStartTabCaptureOnDeviceThread, this,
-          entry->id, request->params(),
-          base::Passed(entry->video_capture_controller()->NewDeviceClient()));
+          entry->id, request->params(), base::Passed(std::move(device_client)));
       break;
 
     case MEDIA_DESKTOP_VIDEO_CAPTURE:
       start_capture_function = base::Bind(
           &VideoCaptureManager::DoStartDesktopCaptureOnDeviceThread, this,
-          entry->id, request->params(),
-          base::Passed(entry->video_capture_controller()->NewDeviceClient()));
+          entry->id, request->params(), base::Passed(std::move(device_client)));
       break;
 
     default: {
       NOTIMPLEMENTED();
       return;
     }
   }
+  // Passing raw pointer |device_client_ptr| is safe, because it will
+  // be owned by the device returned by |start_capture_function|.
   base::PostTaskAndReplyWithResult(
       device_task_runner_.get(), FROM_HERE, start_capture_function,
       base::Bind(&VideoCaptureManager::OnDeviceStarted, this,
-                 request->serial_id()));
+                 request->serial_id(), base::Passed(&frame_buffer_host)));
 }
 
 void VideoCaptureManager::OnDeviceStarted(
     int serial_id,
+    std::unique_ptr<media::FrameBufferHost> frame_buffer_host,
     std::unique_ptr<VideoCaptureDevice> device) {
   DVLOG(3) << __func__;
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK_EQ(serial_id, device_start_queue_.begin()->serial_id());
   // |device| can be null if creation failed in
   //  DoStartDeviceCaptureOnDeviceThread.
   if (device_start_queue_.front().abort_start()) {
     // The device is no longer wanted. Stop the device again.
     DVLOG(3) << "OnDeviceStarted but start request have been aborted.";
     media::VideoCaptureDevice* device_ptr = device.get();
     base::Closure closure =
         base::Bind(&VideoCaptureManager::DoStopDeviceOnDeviceThread, this,
                    base::Passed(&device));
     if (device_ptr && !device_task_runner_->PostTask(FROM_HERE, closure)) {
       // PostTask failed. The device must be stopped anyway.
       device_ptr->StopAndDeAllocate();
     }
   } else {
     DeviceEntry* const entry = GetDeviceEntryBySerialId(serial_id);
     DCHECK(entry);
-    DCHECK(!entry->video_capture_device());
-    // Passing raw pointer |device.get()| to the controller is safe,
-    // because we transfer ownership of it to |entry|. We are calling
-    // SetConsumerFeedbackObserver(nullptr) before releasing
-    // |entry->video_capture_device_| on the |device_task_runner_|.
-    entry->video_capture_controller()->SetConsumerFeedbackObserver(
-        base::MakeUnique<VideoFrameConsumerFeedbackObserverOnTaskRunner>(
-            device.get(), device_task_runner_));
-    entry->SetVideoCaptureDevice(std::move(device));
+    DCHECK(!entry->video_capture_device);
+    if (device) {
+      entry->video_capture_controller->SetFrameBufferHost(
+          std::move(frame_buffer_host));
+      // Passing raw pointer |device.get()| to the controller is safe,
+      // because we transfer ownership of it to |entry|. We are calling
+      // SetConsumerFeedbackObserver(nullptr) before releasing
+      // |entry->video_capture_device_| on the |device_task_runner_|.
+      entry->video_capture_controller->SetConsumerFeedbackObserver(
+          base::MakeUnique<VideoFrameConsumerFeedbackObserverOnTaskRunner>(
+              device.get(), device_task_runner_));
+    }
+    entry->video_capture_device = std::move(device);
 
     if (entry->stream_type == MEDIA_DESKTOP_VIDEO_CAPTURE) {
       const media::VideoCaptureSessionId session_id =
           device_start_queue_.front().session_id();
       DCHECK(session_id != kFakeSessionId);
       MaybePostDesktopCaptureWindowId(session_id);
     }
 
     auto it = photo_request_queue_.begin();
     while (it != photo_request_queue_.end()) {
       auto request = it++;
       DeviceEntry* maybe_entry = GetDeviceEntryBySessionId(request->first);
-      if (maybe_entry && maybe_entry->video_capture_device()) {
-        request->second.Run(maybe_entry->video_capture_device());
+      if (maybe_entry && maybe_entry->video_capture_device) {
+        request->second.Run(maybe_entry->video_capture_device.get());
         photo_request_queue_.erase(request);
       }
     }
   }
 
   device_start_queue_.pop_front();
   HandleQueuedStartRequest();
 }
 
 std::unique_ptr<media::VideoCaptureDevice>
@@ skipping 92 matching lines @@
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DVLOG(1) << __func__ << ", session_id = " << session_id << ", request: "
            << media::VideoCaptureFormat::ToString(params.requested_format);
 
   DeviceEntry* entry = GetOrCreateDeviceEntry(session_id, params);
   if (!entry) {
     done_cb.Run(base::WeakPtr<VideoCaptureController>());
     return;
   }
 
-  DCHECK(entry->video_capture_controller());
+  DCHECK(entry->video_capture_controller);
 
   LogVideoCaptureEvent(VIDEO_CAPTURE_START_CAPTURE);
 
   // First client starts the device.
-  if (!entry->video_capture_controller()->HasActiveClient() &&
-      !entry->video_capture_controller()->HasPausedClient()) {
+  if (!entry->video_capture_controller->HasActiveClient() &&
+      !entry->video_capture_controller->HasPausedClient()) {
     DVLOG(1) << "VideoCaptureManager starting device (type = "
              << entry->stream_type << ", id = " << entry->id << ")";
     QueueStartDevice(session_id, entry, params);
   }
   // Run the callback first, as AddClient() may trigger OnFrameInfo().
-  done_cb.Run(entry->video_capture_controller()->GetWeakPtrForIOThread());
-  entry->video_capture_controller()->AddClient(
-      client_id, client_handler, session_id, params);
+  done_cb.Run(entry->video_capture_controller->GetWeakPtrForIOThread());
+  entry->video_capture_controller->AddClient(client_id, client_handler,
+                                             session_id, params);
 }
 
 void VideoCaptureManager::StopCaptureForClient(
     VideoCaptureController* controller,
     VideoCaptureControllerID client_id,
     VideoCaptureControllerEventHandler* client_handler,
     bool aborted_due_to_error) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(controller);
   DCHECK(client_handler);
@@ skipping 44 matching lines @@
   DCHECK(controller);
   DCHECK(client_handler);
   DeviceEntry* entry = GetDeviceEntryByController(controller);
   if (!entry)
     NOTREACHED() << "Got Null entry while pausing capture";
 
   const bool had_active_client = controller->HasActiveClient();
   controller->PauseClient(client_id, client_handler);
   if (!had_active_client || controller->HasActiveClient())
     return;
-  if (media::VideoCaptureDevice* device = entry->video_capture_device()) {
+  if (media::VideoCaptureDevice* device = entry->video_capture_device.get()) {
     device_task_runner_->PostTask(
         FROM_HERE,
         base::Bind(&VideoCaptureDevice::MaybeSuspend,
                    // Unretained is safe to use here because |device| would be
                    // null if it was scheduled for shutdown and destruction, and
                    // because this task is guaranteed to run before the task
                    // that destroys the |device|.
                    base::Unretained(device)));
   }
 }
 
 void VideoCaptureManager::ResumeCaptureForClient(
     media::VideoCaptureSessionId session_id,
     const media::VideoCaptureParams& params,
     VideoCaptureController* controller,
     VideoCaptureControllerID client_id,
     VideoCaptureControllerEventHandler* client_handler) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(controller);
   DCHECK(client_handler);
 
   DeviceEntry* entry = GetDeviceEntryByController(controller);
   if (!entry)
     NOTREACHED() << "Got Null entry while resuming capture";
 
   const bool had_active_client = controller->HasActiveClient();
   controller->ResumeClient(client_id, client_handler);
   if (had_active_client || !controller->HasActiveClient())
     return;
-  if (media::VideoCaptureDevice* device = entry->video_capture_device()) {
+  if (media::VideoCaptureDevice* device = entry->video_capture_device.get()) {
     device_task_runner_->PostTask(
         FROM_HERE,
         base::Bind(&VideoCaptureDevice::Resume,
                    // Unretained is safe to use here because |device| would be
                    // null if it was scheduled for shutdown and destruction, and
                    // because this task is guaranteed to run before the task
                    // that destroys the |device|.
                    base::Unretained(device)));
   }
 }
 
 void VideoCaptureManager::RequestRefreshFrameForClient(
     VideoCaptureController* controller) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   if (DeviceEntry* entry = GetDeviceEntryByController(controller)) {
-    if (media::VideoCaptureDevice* device = entry->video_capture_device()) {
+    if (media::VideoCaptureDevice* device = entry->video_capture_device.get()) {
       device_task_runner_->PostTask(
           FROM_HERE,
           base::Bind(&VideoCaptureDevice::RequestRefreshFrame,
                      // Unretained is safe to use here because |device| would be
                      // null if it was scheduled for shutdown and destruction,
                      // and because this task is guaranteed to run before the
                      // task that destroys the |device|.
                      base::Unretained(device)));
     }
   }
@@ skipping 27 matching lines @@
   if (it == sessions_.end())
     return false;
   DVLOG(1) << "GetDeviceFormatsInUse for device: " << it->second.name;
 
   // Return the currently in-use format(s) of the device, if it's started.
   DeviceEntry* device_in_use =
       GetDeviceEntryByTypeAndId(it->second.type, it->second.id);
   if (device_in_use) {
     // Currently only one format-in-use is supported at the VCC level.
     formats_in_use->push_back(
-        device_in_use->video_capture_controller()->GetVideoCaptureFormat());
+        device_in_use->video_capture_controller->GetVideoCaptureFormat());
   }
   return true;
 }
 
 void VideoCaptureManager::SetDesktopCaptureWindowId(
     media::VideoCaptureSessionId session_id,
     gfx::NativeViewId window_id) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   VLOG(2) << "SetDesktopCaptureWindowId called for session " << session_id;
 
   notification_window_ids_[session_id] = window_id;
   MaybePostDesktopCaptureWindowId(session_id);
 }
 
 void VideoCaptureManager::MaybePostDesktopCaptureWindowId(
     media::VideoCaptureSessionId session_id) {
   SessionMap::iterator session_it = sessions_.find(session_id);
   if (session_it == sessions_.end())
     return;
 
   DeviceEntry* const existing_device =
       GetDeviceEntryByTypeAndId(session_it->second.type, session_it->second.id);
   if (!existing_device) {
     DVLOG(2) << "Failed to find an existing screen capture device.";
     return;
   }
 
-  if (!existing_device->video_capture_device()) {
+  if (!existing_device->video_capture_device) {
     DVLOG(2) << "Screen capture device not yet started.";
     return;
   }
 
   DCHECK_EQ(MEDIA_DESKTOP_VIDEO_CAPTURE, existing_device->stream_type);
   DesktopMediaID id = DesktopMediaID::Parse(existing_device->id);
   if (id.is_null())
     return;
 
   auto window_id_it = notification_window_ids_.find(session_id);
   if (window_id_it == notification_window_ids_.end()) {
     DVLOG(2) << "Notification window id not set for screen capture.";
     return;
   }
 
   // Post |existing_device->video_capture_device| to the VideoCaptureDevice to
   // the device_task_runner_. This is safe since the device is destroyed on the
   // device_task_runner_.
   device_task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&VideoCaptureManager::SetDesktopCaptureWindowIdOnDeviceThread,
-                 this,
-                 existing_device->video_capture_device(),
+                 this, existing_device->video_capture_device.get(),
                  window_id_it->second));
 
   notification_window_ids_.erase(window_id_it);
 }
 
 void VideoCaptureManager::GetPhotoCapabilities(
     int session_id,
     VideoCaptureDevice::GetPhotoCapabilitiesCallback callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   const DeviceEntry* entry = GetDeviceEntryBySessionId(session_id);
   if (!entry)
     return;
-  VideoCaptureDevice* device = entry->video_capture_device();
+  VideoCaptureDevice* device = entry->video_capture_device.get();
   if (device) {
     VideoCaptureManager::DoGetPhotoCapabilities(std::move(callback), device);
     return;
   }
   // |entry| is known but |device| is nullptr, queue up a request for later.
   photo_request_queue_.emplace_back(
       session_id, base::Bind(&VideoCaptureManager::DoGetPhotoCapabilities, this,
                              base::Passed(&callback)));
 }
 
 void VideoCaptureManager::SetPhotoOptions(
     int session_id,
     media::mojom::PhotoSettingsPtr settings,
     VideoCaptureDevice::SetPhotoOptionsCallback callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   const DeviceEntry* entry = GetDeviceEntryBySessionId(session_id);
   if (!entry)
     return;
-  VideoCaptureDevice* device = entry->video_capture_device();
+  VideoCaptureDevice* device = entry->video_capture_device.get();
   if (device) {
     VideoCaptureManager::DoSetPhotoOptions(std::move(callback),
                                            std::move(settings), device);
     return;
   }
   // |entry| is known but |device| is nullptr, queue up a request for later.
   photo_request_queue_.emplace_back(
       session_id, base::Bind(&VideoCaptureManager::DoSetPhotoOptions, this,
                              base::Passed(&callback), base::Passed(&settings)));
 }
 
 void VideoCaptureManager::TakePhoto(
     int session_id,
     VideoCaptureDevice::TakePhotoCallback callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   const DeviceEntry* entry = GetDeviceEntryBySessionId(session_id);
   if (!entry)
     return;
-  VideoCaptureDevice* device = entry->video_capture_device();
+  VideoCaptureDevice* device = entry->video_capture_device.get();
   if (device) {
     VideoCaptureManager::DoTakePhoto(std::move(callback), device);
     return;
   }
   // |entry| is known but |device| is nullptr, queue up a request for later.
   photo_request_queue_.emplace_back(
       session_id, base::Bind(&VideoCaptureManager::DoTakePhoto, this,
                              base::Passed(&callback)));
 }
 
@@ skipping 87 matching lines @@
     ConsolidateCaptureFormats(&device_info.supported_formats);
     new_devices_info_cache.push_back(device_info);
   }
 
   on_devices_enumerated_callback.Run(new_devices_info_cache);
 }
 
 void VideoCaptureManager::DestroyDeviceEntryIfNoClients(DeviceEntry* entry) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   // Removal of the last client stops the device.
-  if (!entry->video_capture_controller()->HasActiveClient() &&
-      !entry->video_capture_controller()->HasPausedClient()) {
+  if (!entry->video_capture_controller->HasActiveClient() &&
+      !entry->video_capture_controller->HasPausedClient()) {
     DVLOG(1) << "VideoCaptureManager stopping device (type = "
              << entry->stream_type << ", id = " << entry->id << ")";
 
     // The DeviceEntry is removed from |devices_| immediately. The controller is
     // deleted immediately, and the device is freed asynchronously. After this
     // point, subsequent requests to open this same device ID will create a new
     // DeviceEntry, VideoCaptureController, and VideoCaptureDevice.
     DoStopDevice(entry);
     // TODO(mcasas): use a helper function https://crbug.com/624854.
     DeviceEntries::iterator device_it =
@@ skipping 29 matching lines @@
   return nullptr;
 }
 
 VideoCaptureManager::DeviceEntry*
 VideoCaptureManager::GetDeviceEntryByController(
     const VideoCaptureController* controller) const {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   // Look up |controller| in |devices_|.
   for (const std::unique_ptr<DeviceEntry>& device : devices_) {
-    if (device->video_capture_controller() == controller)
+    if (device->video_capture_controller.get() == controller)
       return device.get();
   }
   return nullptr;
 }
 
 VideoCaptureManager::DeviceEntry* VideoCaptureManager::GetDeviceEntryBySerialId(
     int serial_id) const {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   for (const std::unique_ptr<DeviceEntry>& device : devices_) {
@@ skipping 24 matching lines @@
 
   // Check if another session has already opened this device. If so, just
   // use that opened device.
   DeviceEntry* const existing_device =
       GetDeviceEntryByTypeAndId(device_info.type, device_info.id);
   if (existing_device) {
     DCHECK_EQ(device_info.type, existing_device->stream_type);
     return existing_device;
   }
 
-  const int max_buffers = device_info.type == MEDIA_TAB_VIDEO_CAPTURE ?
-      kMaxNumberOfBuffersForTabCapture : kMaxNumberOfBuffers;
-  std::unique_ptr<VideoCaptureController> video_capture_controller(
-      new VideoCaptureController(max_buffers));
-  DeviceEntry* new_device =
+  auto video_capture_controller = base::MakeUnique<VideoCaptureController>();
+  auto new_device_entry =
       new DeviceEntry(device_info.type, device_info.id,
                       std::move(video_capture_controller), params);
-  devices_.emplace_back(new_device);
-  return new_device;
+  devices_.emplace_back(new_device_entry);
+  return new_device_entry;
 }
 
 void VideoCaptureManager::SetDesktopCaptureWindowIdOnDeviceThread(
     media::VideoCaptureDevice* device,
     gfx::NativeViewId window_id) {
   DCHECK(IsOnDeviceThread());
 #if defined(ENABLE_SCREEN_CAPTURE) && !defined(OS_ANDROID)
   DesktopCaptureDevice* desktop_device =
       static_cast<DesktopCaptureDevice*>(device);
   desktop_device->SetNotificationWindowId(window_id);
@@ skipping 65 matching lines @@
   }
 }
 
 void VideoCaptureManager::ResumeDevices() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   for (auto& entry : devices_) {
     // Do not resume Content Video Capture devices, e.g. Tab or Screen capture.
     // Do not try to restart already running devices.
     if (entry->stream_type != MEDIA_DEVICE_VIDEO_CAPTURE ||
-        entry->video_capture_device())
+        entry->video_capture_device)
       continue;
 
     // Check if the device is already in the start queue.
     bool device_in_queue = false;
     for (auto& request : device_start_queue_) {
       if (request.serial_id() == entry->serial_id) {
         device_in_queue = true;
         break;
       }
     }
 
     if (!device_in_queue) {
       // Session ID is only valid for Screen capture. So we can fake it to
       // resume video capture devices here.
       QueueStartDevice(kFakeSessionId, entry.get(), entry->parameters);
     }
   }
 }
 #endif  // defined(OS_ANDROID)
 
 }  // namespace content