Save and provide the context for post-processor of a camera stream
via Camera3RequestDescriptor::StreamBuffer. We extend the structure
to include source and destination buffers for the post processor, along
with CameraStream::Type::Internal buffer pointer (if any). In addition
to that, a back pointer to Camera3RequestDescriptor is convenient to
get access to overall descriptor (status, metadata settings etc.).
Also, migrate CameraStream::process() and PostProcessor::process()
signature to use Camera3RequestDescriptor::StreamBuffer only. This
will be helpful when we move to async post-processing in subsequent
commits.
Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>