[Mojo Video Capture] Decouple VCController from VCBufferPool and VCDeviceClient

content/browser/renderer_host/media/video_capture_controller.h

Index: content/browser/renderer_host/media/video_capture_controller.h
diff --git a/content/browser/renderer_host/media/video_capture_controller.h b/content/browser/renderer_host/media/video_capture_controller.h
index b1a455f2336b03b3300bdde0efd0b4b6886cb0a3..d0ca85bc58354d5ea1de180c47abca0bc1164e1b 100644
--- a/content/browser/renderer_host/media/video_capture_controller.h
+++ b/content/browser/renderer_host/media/video_capture_controller.h
@@ -55,23 +55,27 @@
 #include "media/capture/video_capture_types.h"
 
 namespace media {
-class VideoCaptureBufferPool;
+class FrameBufferPool;
 }
 
 namespace content {
 
 class CONTENT_EXPORT VideoCaptureController : public media::VideoFrameReceiver {
  public:
-  // |max_buffers| is 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).
-  explicit VideoCaptureController(int max_buffers);
+  explicit VideoCaptureController();

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

No longer need 'explicit' here.

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

Done.

   ~VideoCaptureController() override;
 
   base::WeakPtr<VideoCaptureController> GetWeakPtrForIOThread();
 
+  // Factory code creating instances of VideoCaptureController must set a
+  // FrameBufferPool before any of the media::VideoFrameReceiver are used.
+  // Setting the observer is done in this method separate from the constructor
+  // in order to allow use the media::VideoFrameReceiver methods
+  // before the observer can be provided. (This is the case with
+  // VideoCaptureManager).
+  void SetFrameBufferPool(
+      std::unique_ptr<media::FrameBufferPool> frame_buffer_pool);
+
   // Factory code creating instances of VideoCaptureController may optionally
   // set a VideoFrameConsumerFeedbackObserver. Setting the observer is done in
   // this method separate from the constructor to allow clients to create and
@@ -80,10 +84,6 @@ class CONTENT_EXPORT VideoCaptureController : public media::VideoFrameReceiver {
   void SetConsumerFeedbackObserver(
       std::unique_ptr<media::VideoFrameConsumerFeedbackObserver> observer);
 
-  // Return a new VideoCaptureDeviceClient to forward capture events to this
-  // instance.
-  std::unique_ptr<media::VideoCaptureDevice::Client> NewDeviceClient();
-
   // Start video capturing and try to use the resolution specified in |params|.
   // Buffers will be shared to the client as necessary. The client will continue
   // to receive frames from the device until RemoveClient() is called.
@@ -153,7 +153,7 @@ class CONTENT_EXPORT VideoCaptureController : public media::VideoFrameReceiver {
         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);
     ~BufferState();
     BufferState(const BufferState& other);
@@ -163,12 +163,13 @@ class CONTENT_EXPORT VideoCaptureController : public media::VideoFrameReceiver {
     bool HasZeroConsumerHoldCount();
     void SetConsumerFeedbackObserver(
         media::VideoFrameConsumerFeedbackObserver* consumer_feedback_observer);
+    void SetFrameBufferPool(media::FrameBufferPool* frame_buffer_pool);
 
    private:
     const int buffer_id_;
     const int frame_feedback_id_;
     media::VideoFrameConsumerFeedbackObserver* consumer_feedback_observer_;
-    const scoped_refptr<media::VideoCaptureBufferPool> buffer_pool_;
+    media::FrameBufferPool* frame_buffer_pool_;
     const scoped_refptr<media::VideoFrame> frame_;
     double max_consumer_utilization_;
     int consumer_hold_count_;
@@ -188,8 +189,7 @@ class CONTENT_EXPORT VideoCaptureController : public media::VideoFrameReceiver {
   ControllerClient* FindClient(int session_id,
                                const ControllerClients& clients);
 
-  // The pool of shared-memory buffers used for capturing.
-  const scoped_refptr<media::VideoCaptureBufferPool> buffer_pool_;
+  std::unique_ptr<media::FrameBufferPool> frame_buffer_pool_;

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

Nice! Removing the ref-counting is a good sign the object graph has just become
more "untangled." :)

I'm aware the VCBufferPool is still ref-counted, but that's fine since it's
representing a shared data resource, and the ref-counting has been limited to
internal implementation (in the VCManager module).

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

Acknowledged.

 
   std::unique_ptr<media::VideoFrameConsumerFeedbackObserver>
       consumer_feedback_observer_;