Rename and move VCMReceiveStatisticsCallback closer to its users.

The VCMReceiveStatisticsCallback interface is both implemented (by ReceiveStatisticsProxy) and called (by VideoStreamBufferController) in `video/`, so there's no reason it should be declared in `modules/video_coding`. I also took the opportunity to update the name.

No functional changes are intended by this change, but following CLs will make some changes.

Bug: webrtc:15085
Change-Id: Ib8da30ca56675e4f638d0b9778c329b9c1138acf
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/304662
Reviewed-by: Åsa Persson <asapersson@webrtc.org>
Commit-Queue: Rasmus Brandt <brandtr@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#40034}

modules/video_coding/include/video_coding_defines.h

@@ -66,29 +66,6 @@ class VCMReceiveCallback {
   virtual ~VCMReceiveCallback() {}
 };
 
-// Callback class used for informing the user of the incoming bit rate and frame
-// rate.
-class VCMReceiveStatisticsCallback {
- public:
-  virtual void OnCompleteFrame(bool is_keyframe,
-                               size_t size_bytes,
-                               VideoContentType content_type) = 0;
-
-  virtual void OnDroppedFrames(uint32_t frames_dropped) = 0;
-
-  virtual void OnFrameBufferTimingsUpdated(int estimated_max_decode_time_ms,
-                                           int current_delay_ms,
-                                           int target_delay_ms,
-                                           int jitter_buffer_ms,
-                                           int min_playout_delay_ms,
-                                           int render_delay_ms) = 0;
-
-  virtual void OnTimingFrameInfoUpdated(const TimingFrameInfo& info) = 0;
-
- protected:
-  virtual ~VCMReceiveStatisticsCallback() {}
-};
-
 // Callback class used for telling the user about what frame type needed to
 // continue decoding.
 // Typically a key frame when the stream has been corrupted in some way.

video/BUILD.gn

@@ -252,7 +252,6 @@ rtc_library("video_stream_buffer_controller") {
     "../api/video:video_rtp_headers",
     "../modules/video_coding",
     "../modules/video_coding:frame_helpers",
-    "../modules/video_coding:video_codec_interface",
     "../modules/video_coding/timing:inter_frame_delay_variation_calculator",
     "../modules/video_coding/timing:jitter_estimator",
     "../modules/video_coding/timing:timing_module",

video/receive_statistics_proxy.h

@@ -24,7 +24,6 @@
 #include "api/video_codecs/video_decoder.h"
 #include "call/video_receive_stream.h"
 #include "modules/include/module_common_types.h"
-#include "modules/video_coding/include/video_coding_defines.h"
 #include "rtc_base/numerics/histogram_percentile_counter.h"
 #include "rtc_base/numerics/moving_max_counter.h"
 #include "rtc_base/numerics/sample_counter.h"
@@ -35,6 +34,7 @@
 #include "video/quality_threshold.h"
 #include "video/stats_counter.h"
 #include "video/video_quality_observer2.h"
+#include "video/video_stream_buffer_controller.h"
 
 namespace webrtc {
 
@@ -45,7 +45,7 @@ namespace internal {
 // Declared in video_receive_stream2.h.
 struct VideoFrameMetaData;
 
-class ReceiveStatisticsProxy : public VCMReceiveStatisticsCallback,
+class ReceiveStatisticsProxy : public VideoStreamBufferControllerStatsObserver,
                                public RtcpCnameCallback,
                                public RtcpPacketTypeCounterObserver {
  public:
@@ -85,7 +85,7 @@ class ReceiveStatisticsProxy : public VCMReceiveStatisticsCallback,
   // Indicates video stream has been paused (no incoming packets).
   void OnStreamInactive();
 
-  // Overrides VCMReceiveStatisticsCallback.
+  // Implements VideoStreamBufferControllerStatsObserver.
   void OnCompleteFrame(bool is_keyframe,
                        size_t size_bytes,
                        VideoContentType content_type) override;
@@ -99,10 +99,10 @@ class ReceiveStatisticsProxy : public VCMReceiveStatisticsCallback,
 
   void OnTimingFrameInfoUpdated(const TimingFrameInfo& info) override;
 
-  // Overrides RtcpCnameCallback.
+  // Implements RtcpCnameCallback.
   void OnCname(uint32_t ssrc, absl::string_view cname) override;
 
-  // Overrides RtcpPacketTypeCounterObserver.
+  // Implements RtcpPacketTypeCounterObserver.
   void RtcpPacketTypesCounterUpdated(
       uint32_t ssrc,
       const RtcpPacketTypeCounter& packet_counter) override;

video/video_stream_buffer_controller.cc

@@ -79,7 +79,7 @@ VideoStreamBufferController::VideoStreamBufferController(
     Clock* clock,
     TaskQueueBase* worker_queue,
     VCMTiming* timing,
-    VCMReceiveStatisticsCallback* stats_proxy,
+    VideoStreamBufferControllerStatsObserver* stats_proxy,
     FrameSchedulingReceiver* receiver,
     TimeDelta max_wait_for_keyframe,
     TimeDelta max_wait_for_frame,

video/video_stream_buffer_controller.h

@@ -17,7 +17,6 @@
 #include "api/task_queue/task_queue_base.h"
 #include "api/video/encoded_frame.h"
 #include "api/video/frame_buffer.h"
-#include "modules/video_coding/include/video_coding_defines.h"
 #include "modules/video_coding/timing/inter_frame_delay_variation_calculator.h"
 #include "modules/video_coding/timing/jitter_estimator.h"
 #include "modules/video_coding/timing/timing.h"
@@ -36,13 +35,33 @@ class FrameSchedulingReceiver {
   virtual void OnDecodableFrameTimeout(TimeDelta wait_time) = 0;
 };
 
+class VideoStreamBufferControllerStatsObserver {
+ public:
+  virtual ~VideoStreamBufferControllerStatsObserver() = default;
+
+  virtual void OnCompleteFrame(bool is_keyframe,
+                               size_t size_bytes,
+                               VideoContentType content_type) = 0;
+
+  virtual void OnDroppedFrames(uint32_t frames_dropped) = 0;
+
+  virtual void OnFrameBufferTimingsUpdated(int estimated_max_decode_time_ms,
+                                           int current_delay_ms,
+                                           int target_delay_ms,
+                                           int jitter_buffer_ms,
+                                           int min_playout_delay_ms,
+                                           int render_delay_ms) = 0;
+
+  virtual void OnTimingFrameInfoUpdated(const TimingFrameInfo& info) = 0;
+};
+
 class VideoStreamBufferController {
  public:
   VideoStreamBufferController(
       Clock* clock,
       TaskQueueBase* worker_queue,
       VCMTiming* timing,
-      VCMReceiveStatisticsCallback* stats_proxy,
+      VideoStreamBufferControllerStatsObserver* stats_proxy,
       FrameSchedulingReceiver* receiver,
       TimeDelta max_wait_for_keyframe,
       TimeDelta max_wait_for_frame,
@@ -78,7 +97,7 @@ class VideoStreamBufferController {
   const absl::optional<RttMultExperiment::Settings> rtt_mult_settings_ =
       RttMultExperiment::GetRttMultValue();
   Clock* const clock_;
-  VCMReceiveStatisticsCallback* const stats_proxy_;
+  VideoStreamBufferControllerStatsObserver* const stats_proxy_;
   FrameSchedulingReceiver* const receiver_;
   VCMTiming* const timing_;
   const std::unique_ptr<FrameDecodeScheduler> frame_decode_scheduler_

video/video_stream_buffer_controller_unittest.cc

@@ -95,7 +95,8 @@ class VCMTimingTest : public VCMTiming {
               ());
 };
 
-class VCMReceiveStatisticsCallbackMock : public VCMReceiveStatisticsCallback {
+class VideoStreamBufferControllerStatsObserverMock
+    : public VideoStreamBufferControllerStatsObserver {
  public:
   MOCK_METHOD(void,
               OnCompleteFrame,
@@ -225,7 +226,8 @@ class VideoStreamBufferControllerFixture
   DecodeSynchronizer decode_sync_;
 
   ::testing::NiceMock<VCMTimingTest> timing_;
-  ::testing::NiceMock<VCMReceiveStatisticsCallbackMock> stats_callback_;
+  ::testing::NiceMock<VideoStreamBufferControllerStatsObserverMock>
+      stats_callback_;
   std::unique_ptr<VideoStreamBufferController> buffer_;
 
  private: