That is, rather than keeping a separate pointer and size.
This helps automate memory management in NetEq and will be useful in the
work to minimize the AudioDecoder interface as part of the injectable
audio codec work.
I'm planning a follow-up that will change the current management of Packet* to wrapping them in unique_ptr instead.
Review-Url: https://codereview.webrtc.org/2289093003
Cr-Commit-Position: refs/heads/master@{#14002}