[Mojo Video Capture] Do not instantiate in-process VideoCaptureSystem when using service

content/browser/renderer_host/media/in_process_video_capture_device_launcher.cc

Index: content/browser/renderer_host/media/in_process_video_capture_device_launcher.cc
diff --git a/content/browser/renderer_host/media/in_process_video_capture_device_launcher.cc b/content/browser/renderer_host/media/in_process_video_capture_device_launcher.cc
index f34de98ff20cb09a577c667e02273e03c2356080..9445624f1e38edfeed14f141ba3c2a60310091f3 100644
--- a/content/browser/renderer_host/media/in_process_video_capture_device_launcher.cc
+++ b/content/browser/renderer_host/media/in_process_video_capture_device_launcher.cc
@@ -92,6 +92,11 @@ void InProcessVideoCaptureDeviceLauncher::LaunchDeviceAsync(
 
   switch (stream_type) {
     case MEDIA_DEVICE_VIDEO_CAPTURE: {
+      if (!video_capture_system_) {
+        callbacks->OnDeviceLaunchFailed();

[emircan, 2017/05/18 18:40:16]

This becomes the second caller of OnDeviceLaunchFailed(). I think you should add
some logs to explain why it failed to distinguish between failures.

[chfremer, 2017/05/18 19:03:21]

Good point. I realized that this code path is actually expected to never be
reached, so instead of adding the logging, I am proposing to use a NOTREACHED
here.

Done.

+        base::ResetAndReturn(&done_cb).Run();
+        return;
+      }
       start_capture_closure =
           base::Bind(&InProcessVideoCaptureDeviceLauncher::
                          DoStartDeviceCaptureOnDeviceThread,
@@ -165,9 +170,11 @@ void InProcessVideoCaptureDeviceLauncher::OnDeviceStarted(
     switch (state_copy) {
       case State::DEVICE_START_IN_PROGRESS:
         callbacks->OnDeviceLaunchFailed();
+        base::ResetAndReturn(&done_cb).Run();
         return;
       case State::DEVICE_START_ABORTING:
         callbacks->OnDeviceLaunchAborted();
+        base::ResetAndReturn(&done_cb).Run();
         return;
       case State::READY_TO_LAUNCH:
         NOTREACHED();
@@ -181,16 +188,17 @@ void InProcessVideoCaptureDeviceLauncher::OnDeviceStarted(
   switch (state_copy) {
     case State::DEVICE_START_IN_PROGRESS:
       callbacks->OnDeviceLaunched(std::move(launched_device));
+      base::ResetAndReturn(&done_cb).Run();
       return;
     case State::DEVICE_START_ABORTING:
       launched_device.reset();
       callbacks->OnDeviceLaunchAborted();
+      base::ResetAndReturn(&done_cb).Run();
       return;
     case State::READY_TO_LAUNCH:
       NOTREACHED();
       return;
   }
-  base::ResetAndReturn(&done_cb).Run();
 }
 
 void InProcessVideoCaptureDeviceLauncher::DoStartDeviceCaptureOnDeviceThread(
@@ -200,6 +208,7 @@ void InProcessVideoCaptureDeviceLauncher::DoStartDeviceCaptureOnDeviceThread(
     ReceiveDeviceCallback result_callback) {
   SCOPED_UMA_HISTOGRAM_TIMER("Media.VideoCaptureManager.StartDeviceTime");
   DCHECK(device_task_runner_->BelongsToCurrentThread());
+  DCHECK(video_capture_system_);
 
   std::unique_ptr<media::VideoCaptureDevice> video_capture_device =
       video_capture_system_->CreateDevice(device_id);