[Mojo Video Capture] Decouple VCController from VCBufferPool and VCDeviceClient

content/browser/renderer_host/media/video_capture_controller.cc

Index: content/browser/renderer_host/media/video_capture_controller.cc
diff --git a/content/browser/renderer_host/media/video_capture_controller.cc b/content/browser/renderer_host/media/video_capture_controller.cc
index 5f226b65422b880d21a94c1fe6795ede553eb2a5..ba64d2534d59785ac49e02ff27aba7a2610052df 100644
--- a/content/browser/renderer_host/media/video_capture_controller.cc
+++ b/content/browser/renderer_host/media/video_capture_controller.cc
@@ -18,12 +18,11 @@
 #include "build/build_config.h"
 #include "components/display_compositor/gl_helper.h"
 #include "content/browser/renderer_host/media/media_stream_manager.h"
-#include "content/browser/renderer_host/media/video_capture_gpu_jpeg_decoder.h"
 #include "content/browser/renderer_host/media/video_capture_manager.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/common/content_switches.h"
 #include "media/base/video_frame.h"
-#include "media/capture/video/video_capture_buffer_pool_impl.h"
+#include "media/capture/video/video_capture_buffer_pool.h"
 #include "media/capture/video/video_capture_buffer_tracker_factory_impl.h"
 #include "media/capture/video/video_capture_device_client.h"
 
@@ -46,50 +45,6 @@ static const int kInfiniteRatio = 99999;
         name, \
         (height) ? ((width) * 100) / (height) : kInfiniteRatio);
 
-std::unique_ptr<media::VideoCaptureJpegDecoder> CreateGpuJpegDecoder(
-    const media::VideoCaptureJpegDecoder::DecodeDoneCB& decode_done_cb) {
-  return base::MakeUnique<VideoCaptureGpuJpegDecoder>(decode_done_cb);
-}
-
-// Decorator for media::VideoFrameReceiver that forwards all incoming calls
-// to the Browser IO thread.
-class VideoFrameReceiverOnIOThread : public media::VideoFrameReceiver {
- public:
-  explicit VideoFrameReceiverOnIOThread(
-      const base::WeakPtr<VideoFrameReceiver>& receiver)
-      : receiver_(receiver) {}
-
-  void OnIncomingCapturedVideoFrame(
-      std::unique_ptr<media::VideoCaptureDevice::Client::Buffer> buffer,
-      scoped_refptr<media::VideoFrame> frame) override {
-    BrowserThread::PostTask(
-        BrowserThread::IO, FROM_HERE,
-        base::Bind(&VideoFrameReceiver::OnIncomingCapturedVideoFrame, receiver_,
-                   base::Passed(&buffer), std::move(frame)));
-  }
-
-  void OnError() override {
-    BrowserThread::PostTask(
-        BrowserThread::IO, FROM_HERE,
-        base::Bind(&VideoFrameReceiver::OnError, receiver_));
-  }
-
-  void OnLog(const std::string& message) override {
-    BrowserThread::PostTask(
-        BrowserThread::IO, FROM_HERE,
-        base::Bind(&VideoFrameReceiver::OnLog, receiver_, message));
-  }
-
-  void OnBufferDestroyed(int buffer_id_to_drop) override {
-    BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
-                            base::Bind(&VideoFrameReceiver::OnBufferDestroyed,
-                                       receiver_, buffer_id_to_drop));
-  }
-
- private:
-  base::WeakPtr<VideoFrameReceiver> receiver_;
-};
-
 }  // anonymous namespace
 
 struct VideoCaptureController::ControllerClient {
@@ -140,12 +95,12 @@ VideoCaptureController::BufferState::BufferState(
     int buffer_id,
     int frame_feedback_id,
     media::VideoFrameConsumerFeedbackObserver* consumer_feedback_observer,
-    scoped_refptr<media::VideoCaptureBufferPool> buffer_pool,
+    media::FrameBufferPool* frame_buffer_pool,
     scoped_refptr<media::VideoFrame> frame)
     : buffer_id_(buffer_id),
       frame_feedback_id_(frame_feedback_id),
       consumer_feedback_observer_(consumer_feedback_observer),
-      buffer_pool_(std::move(buffer_pool)),
+      frame_buffer_pool_(frame_buffer_pool),
       frame_(std::move(frame)),
       max_consumer_utilization_(
           media::VideoFrameConsumerFeedbackObserver::kNoUtilizationRecorded),
@@ -166,7 +121,8 @@ void VideoCaptureController::BufferState::RecordConsumerUtilization(
 
 void VideoCaptureController::BufferState::IncreaseConsumerCount() {
   if (consumer_hold_count_ == 0)
-    buffer_pool_->HoldForConsumers(buffer_id_, 1);
+    if (frame_buffer_pool_ != nullptr)

[miu, 2016/12/13 21:11:10]

Instead of nesting if-statements, consider consolidating into one expression:

  if (frame_buffer_pool_ && consumer_hold_count_ == 0)
    ...

[chfremer, 2016/12/13 23:12:39]

In this case, we have the statement in l.125 to be conditioned only by the first
"if", 
that's why I went for the nested ifs. Are there better alternatives?

+      frame_buffer_pool_->SetBufferHold(buffer_id_);
   consumer_hold_count_++;
 }
 
@@ -179,7 +135,8 @@ void VideoCaptureController::BufferState::DecreaseConsumerCount() {
       consumer_feedback_observer_->OnUtilizationReport(
           frame_feedback_id_, max_consumer_utilization_);
     }
-    buffer_pool_->RelinquishConsumerHold(buffer_id_, 1);
+    if (frame_buffer_pool_ != nullptr)
+      frame_buffer_pool_->ReleaseBufferHold(buffer_id_);
     max_consumer_utilization_ =
         media::VideoFrameConsumerFeedbackObserver::kNoUtilizationRecorded;
   }
@@ -194,10 +151,13 @@ void VideoCaptureController::BufferState::SetConsumerFeedbackObserver(
   consumer_feedback_observer_ = consumer_feedback_observer;
 }
 
-VideoCaptureController::VideoCaptureController(int max_buffers)
-    : buffer_pool_(new media::VideoCaptureBufferPoolImpl(
-          base::MakeUnique<media::VideoCaptureBufferTrackerFactoryImpl>(),
-          max_buffers)),
+void VideoCaptureController::BufferState::SetFrameBufferPool(
+    media::FrameBufferPool* frame_buffer_pool) {
+  frame_buffer_pool_ = frame_buffer_pool;
+}
+
+VideoCaptureController::VideoCaptureController()
+    : frame_buffer_pool_(nullptr),
       consumer_feedback_observer_(nullptr),
       state_(VIDEO_CAPTURE_STATE_STARTED),
       has_received_frames_(false),
@@ -205,11 +165,22 @@ VideoCaptureController::VideoCaptureController(int max_buffers)
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 }
 
+VideoCaptureController::~VideoCaptureController() = default;
+
 base::WeakPtr<VideoCaptureController>
 VideoCaptureController::GetWeakPtrForIOThread() {
   return weak_ptr_factory_.GetWeakPtr();
 }
 
+void VideoCaptureController::SetFrameBufferPool(
+    std::unique_ptr<media::FrameBufferPool> frame_buffer_pool) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  frame_buffer_pool_ = std::move(frame_buffer_pool);
+  // Update existing BufferState entries.
+  for (auto& entry : buffer_id_to_state_map_)
+    entry.second.SetFrameBufferPool(frame_buffer_pool_.get());
+}
+
 void VideoCaptureController::SetConsumerFeedbackObserver(
     std::unique_ptr<media::VideoFrameConsumerFeedbackObserver>
         consumer_feedback_observer) {
@@ -220,18 +191,6 @@ void VideoCaptureController::SetConsumerFeedbackObserver(
     entry.second.SetConsumerFeedbackObserver(consumer_feedback_observer_.get());
 }
 
-std::unique_ptr<media::VideoCaptureDevice::Client>
-VideoCaptureController::NewDeviceClient() {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-  return base::MakeUnique<media::VideoCaptureDeviceClient>(
-      base::MakeUnique<VideoFrameReceiverOnIOThread>(
-          this->GetWeakPtrForIOThread()),
-      buffer_pool_,
-      base::Bind(&CreateGpuJpegDecoder,
-                 base::Bind(&VideoFrameReceiver::OnIncomingCapturedVideoFrame,
-                            this->GetWeakPtrForIOThread())));
-}
-
 void VideoCaptureController::AddClient(
     VideoCaptureControllerID id,
     VideoCaptureControllerEventHandler* event_handler,
@@ -410,13 +369,11 @@ VideoCaptureController::GetVideoCaptureFormat() const {
   return video_capture_format_;
 }
 
-VideoCaptureController::~VideoCaptureController() {
-}
-
 void VideoCaptureController::OnIncomingCapturedVideoFrame(
     std::unique_ptr<media::VideoCaptureDevice::Client::Buffer> buffer,
     scoped_refptr<VideoFrame> frame) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DCHECK(frame_buffer_pool_);
   const int buffer_id = buffer->id();
   DCHECK_NE(buffer_id, media::VideoCaptureBufferPool::kInvalidId);
 
@@ -426,7 +383,7 @@ void VideoCaptureController::OnIncomingCapturedVideoFrame(
           .insert(std::make_pair(
               buffer_id, BufferState(buffer_id, buffer->frame_feedback_id(),
                                      consumer_feedback_observer_.get(),
-                                     buffer_pool_, frame)))
+                                     frame_buffer_pool_.get(), frame)))
           .first;
   BufferState& buffer_state = it->second;
   DCHECK(buffer_state.HasZeroConsumerHoldCount());
@@ -520,6 +477,7 @@ void VideoCaptureController::OnLog(const std::string& message) {
 
 void VideoCaptureController::OnBufferDestroyed(int buffer_id_to_drop) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DCHECK(frame_buffer_pool_);
 
   for (const auto& client : controller_clients_) {
     if (client->session_closed)
@@ -544,10 +502,11 @@ void VideoCaptureController::DoNewBufferOnIOThread(
     const scoped_refptr<media::VideoFrame>& frame) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK_EQ(media::VideoFrame::STORAGE_SHMEM, frame->storage_type());
+  CHECK(frame_buffer_pool_);

[miu, 2016/12/13 21:11:10]

DCHECK instead of CHECK?

Actually, the since |frame_buffer_pool_| is a std::unique_ptr; I believe
dereferencing it in the method call below will execute an assertion that checks
for not-null. So, you probably don't need this.

[chfremer, 2016/12/13 23:12:39]

Done.

 
   const int buffer_id = buffer->id();
   mojo::ScopedSharedBufferHandle handle =
-      buffer_pool_->GetHandleForTransit(buffer_id);
+      frame_buffer_pool_->GetHandleForTransit(buffer_id);
   client->event_handler->OnBufferCreated(client->controller_id,
                                          std::move(handle),
                                          buffer->mapped_size(), buffer_id);