Support external buffer import in VDA interface and add a V4L2SVDA impl.

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..69f4321888a2bba0db8050af87e1dd80243e7baa 100644
--- a/content/common/gpu/media/v4l2_slice_video_decode_accelerator.h
+++ b/content/common/gpu/media/v4l2_slice_video_decode_accelerator.h
@@ -48,6 +48,9 @@ class CONTENT_EXPORT V4L2SliceVideoDecodeAccelerator
   void Decode(const media::BitstreamBuffer& bitstream_buffer) override;
   void AssignPictureBuffers(
       const std::vector<media::PictureBuffer>& buffers) override;
+  void ImportBufferForPicture(int32_t picture_buffer_id,
+                              const std::vector<gfx::GpuMemoryBufferHandle>&
+                                  gpu_memory_buffer_handles) override;
   void ReusePictureBuffer(int32_t picture_buffer_id) override;
   void Flush() override;
   void Reset() override;
@@ -56,6 +59,7 @@ class CONTENT_EXPORT V4L2SliceVideoDecodeAccelerator
       const base::WeakPtr<Client>& decode_client,
       const scoped_refptr<base::SingleThreadTaskRunner>& decode_task_runner)
       override;
+  media::VideoPixelFormat GetOutputFormat() const override;
 
   static media::VideoDecodeAccelerator::SupportedProfiles
       GetSupportedProfiles();
@@ -80,8 +84,10 @@ class CONTENT_EXPORT V4L2SliceVideoDecodeAccelerator
     bool at_device;

[kcwu, 2016/03/22 05:42:54]

How about merge |at_device| and |at_client| as single enum to indicate the
ownership and states?
Since 
1. they are not independent (it's not possible true for both at the same time)
2. there is special state now.
v4l2_slice_vda.cc line 1523, it sets output_record.at_client = true but not
really "at client";

     bool at_client;
     int32_t picture_id;
+    GLuint texture_id;
     EGLImageKHR egl_image;
     EGLSyncKHR egl_sync;
+    std::vector<base::ScopedFD> dmabuf_fds;
     bool cleared;
   };
 
@@ -209,19 +215,32 @@ class CONTENT_EXPORT V4L2SliceVideoDecodeAccelerator
   // 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);
+      const std::vector<media::PictureBuffer>& buffers);
+
+  void ImportBufferForPictureTask(
+      int32_t picture_buffer_id,
+      // TODO(posciak): (crbug.com/561749) we should normally be able to pass
+      // the vector by itself via std::move, but it's not possible to do this
+      // if this method is used as a callback.
+      scoped_ptr<std::vector<base::ScopedFD>> passed_dmabuf_fds);
+
+  void CreateEGLImageFor(
+      size_t buffer_index,
+      // TODO(posciak): (crbug.com/561749) we should normally be able to pass
+      // the vector by itself via std::move, but it's not possible to do this
+      // if this method is used as a callback.
+      scoped_ptr<std::vector<base::ScopedFD>> passed_dmabuf_fds,
+      GLuint texture_id,
+      const gfx::Size& size,
+      uint32_t fourcc);
+
+  void AssignEGLImage(
+      size_t buffer_index,
+      EGLImageKHR egl_image,
+      // TODO(posciak): (crbug.com/561749) we should normally be able to pass
+      // the vector by itself via std::move, but it's not possible to do this
+      // if this method is used as a callback.
+      scoped_ptr<std::vector<base::ScopedFD>> passed_dmabuf_fds);
 
   // Process pending events, if any.
   void ProcessPendingEventsIfNeeded();
@@ -367,6 +386,8 @@ class CONTENT_EXPORT V4L2SliceVideoDecodeAccelerator
   // Decoder state.
   State state_;
 
+  Config::OutputMode output_mode_;
+
   // If any of these are true, we are waiting for the device to finish decoding
   // all previously-queued frames, so we can finish the flush/reset/surface
   // change flows. These can stack.