Reland: VideoCapture: migrate VideoCapture renderer-->host messages to mojo, part 1

content/renderer/media/video_capture_impl.cc

Index: content/renderer/media/video_capture_impl.cc
diff --git a/content/renderer/media/video_capture_impl.cc b/content/renderer/media/video_capture_impl.cc
index 583fb97bb9e68b9fffc02977cecb96879447632e..c4bf09fe5420e88f92c18257d37061005138bf06 100644
--- a/content/renderer/media/video_capture_impl.cc
+++ b/content/renderer/media/video_capture_impl.cc
@@ -111,6 +111,7 @@ VideoCaptureImpl::VideoCaptureImpl(
     : message_filter_(filter),
       device_id_(0),
       session_id_(session_id),
+      video_capture_service_for_testing_(nullptr),
       suspended_(false),
       state_(VIDEO_CAPTURE_STATE_STOPPED),
       io_task_runner_(std::move(io_task_runner)),
@@ -124,16 +125,16 @@ VideoCaptureImpl::VideoCaptureImpl(
 VideoCaptureImpl::~VideoCaptureImpl() {
   DCHECK(io_task_runner_->BelongsToCurrentThread());
   if (state_ == VIDEO_CAPTURE_STATE_STARTED)
-    Send(new VideoCaptureHostMsg_Stop(device_id_));
+    GetVideoCaptureService()->Stop(device_id_);
   message_filter_->RemoveDelegate(this);
 }
 
 void VideoCaptureImpl::SuspendCapture(bool suspend) {
   DCHECK(io_task_runner_->BelongsToCurrentThread());
-  Send(suspend ? static_cast<IPC::Message*>(
-                     new VideoCaptureHostMsg_Pause(device_id_))
-               : static_cast<IPC::Message*>(new VideoCaptureHostMsg_Resume(
-                     device_id_, session_id_, params_)));
+  if (suspend)
+    GetVideoCaptureService()->Pause(device_id_);
+  else
+    Send(new VideoCaptureHostMsg_Resume(device_id_, session_id_, params_));
 }
 
 void VideoCaptureImpl::StartCapture(
@@ -198,36 +199,38 @@ void VideoCaptureImpl::StopCapture(int client_id) {
     }
   }
 
-  if (clients_.empty()) {
-    DVLOG(1) << "StopCapture: No more client, stopping ...";
-    StopDevice();
-    client_buffers_.clear();
-    client_buffer2s_.clear();
-    weak_factory_.InvalidateWeakPtrs();
-  }
+  if (!clients_.empty())
+    return;
+  DVLOG(1) << "StopCapture: No more client, stopping ...";
+  StopDevice();
+  client_buffers_.clear();
+  client_buffer2s_.clear();
+  weak_factory_.InvalidateWeakPtrs();
 }
 
 void VideoCaptureImpl::RequestRefreshFrame() {
   DCHECK(io_task_runner_->BelongsToCurrentThread());
-  Send(new VideoCaptureHostMsg_RequestRefreshFrame(device_id_));
+  GetVideoCaptureService()->RequestRefreshFrame(device_id_);
 }
 
 void VideoCaptureImpl::GetDeviceSupportedFormats(
     const VideoCaptureDeviceFormatsCB& callback) {
   DCHECK(io_task_runner_->BelongsToCurrentThread());
   device_formats_cb_queue_.push_back(callback);
-  if (device_formats_cb_queue_.size() == 1)
+  if (device_formats_cb_queue_.size() == 1) {
     Send(new VideoCaptureHostMsg_GetDeviceSupportedFormats(device_id_,
                                                            session_id_));
+  }
 }
 
 void VideoCaptureImpl::GetDeviceFormatsInUse(
     const VideoCaptureDeviceFormatsCB& callback) {
   DCHECK(io_task_runner_->BelongsToCurrentThread());
   device_formats_in_use_cb_queue_.push_back(callback);
-  if (device_formats_in_use_cb_queue_.size() == 1)
+  if (device_formats_in_use_cb_queue_.size() == 1) {
     Send(
         new VideoCaptureHostMsg_GetDeviceFormatsInUse(device_id_, session_id_));
+  }
 }
 
 void VideoCaptureImpl::OnBufferCreated(base::SharedMemoryHandle handle,
@@ -497,12 +500,11 @@ void VideoCaptureImpl::OnDelegateAdded(int32_t device_id) {
 
 void VideoCaptureImpl::StopDevice() {
   DCHECK(io_task_runner_->BelongsToCurrentThread());
-
-  if (state_ == VIDEO_CAPTURE_STATE_STARTED) {
-    state_ = VIDEO_CAPTURE_STATE_STOPPING;
-    Send(new VideoCaptureHostMsg_Stop(device_id_));
-    params_.requested_format.frame_size.SetSize(0, 0);
-  }
+  if (state_ != VIDEO_CAPTURE_STATE_STARTED)
+    return;
+  state_ = VIDEO_CAPTURE_STATE_STOPPING;
+  GetVideoCaptureService()->Stop(device_id_);
+  params_.requested_format.frame_size.SetSize(0, 0);
 }
 
 void VideoCaptureImpl::RestartCapture() {
@@ -552,6 +554,20 @@ bool VideoCaptureImpl::RemoveClient(int client_id, ClientInfoMap* clients) {
   return found;
 }
 
+mojom::VideoCaptureService* VideoCaptureImpl::GetVideoCaptureService() {
+  DCHECK(io_task_runner_->BelongsToCurrentThread());
+  if (video_capture_service_for_testing_)
+    return video_capture_service_for_testing_;
+  if (video_capture_service_.get())

[Ken Rockot(use gerrit already), 2016/10/05 20:59:44]

minor nit: a more common pattern is

if (!foo.get()) {
  // initialize foo
}
return foo.get()

fewer return paths generally feels less confusing imho

[mcasas, 2016/10/05 22:23:50]

Done.

+    return video_capture_service_.get();
+
+  DCHECK(message_filter_->sender());
+  message_filter_->sender()
+      ->GetAssociatedInterfaceSupport()
+      ->GetRemoteAssociatedInterface(&video_capture_service_);
+  return video_capture_service_.get();
+};
+
 // static
 void VideoCaptureImpl::DidFinishConsumingFrame(
     const media::VideoFrameMetadata* metadata,