Revert "V4L2SVDA: Move allocation from GPU Child thread to decoder thread."

content/common/gpu/media/v4l2_slice_video_decode_accelerator.h

Index: content/common/gpu/media/v4l2_slice_video_decode_accelerator.h
diff --git a/content/common/gpu/media/v4l2_slice_video_decode_accelerator.h b/content/common/gpu/media/v4l2_slice_video_decode_accelerator.h
index 9171e442b8cc1adad2af47b8f3d0bc52920c9e93..cc11da302a160fd31f7fda734e08b3d8c6d54c62 100644
--- a/content/common/gpu/media/v4l2_slice_video_decode_accelerator.h
+++ b/content/common/gpu/media/v4l2_slice_video_decode_accelerator.h
@@ -157,21 +157,21 @@ class CONTENT_EXPORT V4L2SliceVideoDecodeAccelerator
 
   // Dismiss all |picture_buffer_ids| via Client::DismissPictureBuffer()
   // and signal |done| after finishing.
-  void DismissPictures(const std::vector<int32_t>& picture_buffer_ids,
+  void DismissPictures(std::vector<int32_t> picture_buffer_ids,
                        base::WaitableEvent* done);
 
   // Task to finish initialization on decoder_thread_.
   void InitializeTask();
 
   // Surface set change (resolution change) flow.
-  // If we have no surfaces allocated, start it immediately, otherwise mark
-  // ourselves as pending for surface set change.
+  // If we have no surfaces allocated, just allocate them and return.
+  // Otherwise mark us as pending for surface set change.
   void InitiateSurfaceSetChange();
   // If a surface set change is pending and we are ready, stop the device,
   // destroy outputs, releasing resources and dismissing pictures as required,
-  // followed by starting the flow to allocate a new set for the current
-  // resolution/DPB size, as provided by decoder.
-  bool FinishSurfaceSetChange();
+  // followed by allocating a new set for the new resolution/DPB size
+  // as provided by decoder. Finally, try to resume decoding.
+  void FinishSurfaceSetChangeIfNeeded();
 
   void NotifyError(Error error);
   void DestroyTask();
@@ -189,41 +189,20 @@ class CONTENT_EXPORT V4L2SliceVideoDecodeAccelerator
   // Tell the decoder to flush all frames, reset it and mark us as scheduled
   // for flush, so that we can finish it once all pending decodes are finished.
   void InitiateFlush();
-  // To be called if decoder_flushing_ is true. If not all pending frames are
-  // decoded, return false, requesting the caller to try again later.
-  // Otherwise perform flush by sending all pending pictures to the client,
-  // notify it that flush is finished and return true, informing the caller
-  // that further progress can be made.
-  bool FinishFlush();
+  // If all pending frames are decoded and we are waiting to flush, perform it.
+  // This will send all pending pictures to client and notify the client that
+  // flush is complete and puts us in a state ready to resume.
+  void FinishFlushIfNeeded();
 
   // Reset flow when requested by client.
-  // Drop all inputs, reset the decoder and mark us as pending for reset.
+  // Drop all inputs and reset the decoder and mark us as pending for reset.
   void ResetTask();
-  // To be called if decoder_resetting_ is true. If not all pending frames are
-  // decoded, return false, requesting the caller to try again later.
-  // Otherwise perform reset by dropping all pending outputs (client is not
-  // interested anymore), notifying it that reset is finished, and return true,
-  // informing the caller that further progress can be made.
-  bool FinishReset();
-
-  // Allocate V4L2 buffers and assign them to |buffers| provided by the client
-  // via AssignPictureBuffers() on decoder thread.
-  void AssignPictureBuffersTask(
-    const std::vector<media::PictureBuffer>& buffers);
-
-  // Create EGLImages bound to textures in |buffers| for given
-  // |output_format_fourcc| and |output_planes_count|.
-  void CreateEGLImages(const std::vector<media::PictureBuffer>& buffers,
-                       uint32_t output_format_fourcc,
-                       size_t output_planes_count);
-
-  // Assign |egl_images| to previously-allocated V4L2 buffers in
-  // output_buffer_map_ and picture ids from |buffers| and finish the surface
-  // change sequence.
-  void AssignEGLImages(const std::vector<media::PictureBuffer>& buffers,
-                       const std::vector<EGLImageKHR>& egl_images);
-
-  // Process pending events, if any.
+  // If all pending frames are decoded and we are waiting to reset, perform it.
+  // This drops all pending outputs (client is not interested anymore),
+  // notifies the client we are done and puts us in a state ready to resume.
+  void FinishResetIfNeeded();
+
+  // Process pending events if any.
   void ProcessPendingEventsIfNeeded();
 
   // Performed on decoder_thread_ as a consequence of poll() on decoder_thread_
@@ -400,6 +379,10 @@ class CONTENT_EXPORT V4L2SliceVideoDecodeAccelerator
   // The number of pictures that are sent to PictureReady and will be cleared.
   int picture_clearing_count_;
 
+  // Used by the decoder thread to wait for AssignPictureBuffers to arrive
+  // to avoid races with potential Reset requests.
+  base::WaitableEvent pictures_assigned_;
+
   // EGL state
   EGLDisplay egl_display_;