Remove final from rtc::Buffer.

Remove final from rtc::Buffer.

With it removed, you can now use it with scoped_refptr by wrapping it in
an rtc::RefCountedObject<rtc::Buffer>.

BUG=

Committed: https://crrev.com/27dfe201a55b345c17ca4586a5a5a3a9ab245ee9
Cr-Commit-Position: refs/heads/master@{#10386}

[noahric, 2015-10-22 21:08:41]

noahric@chromium.org changed reviewers:
+ kwiberg@webrtc.org, tommi@webrtc.org

[kwiberg-webrtc, 2015-10-22 21:12:51]

lgtm

As discussed in a previous incarnation of this CL that is no longer with us,
this is a reasonable price to pay to avoid some considerable pain elsewhere.

[noahric, 2015-10-22 21:16:34]

On 2015/10/22 21:12:51, kwiberg-webrtc wrote:
> lgtm
> 
> As discussed in a previous incarnation of this CL that is no longer with us,
> this is a reasonable price to pay to avoid some considerable pain elsewhere.

Thanks, and sorry for the runaround on deleting the issue.

And it turns out the code I included on the other issue doesn't actually work
anyways, the buffer is getting std::moved at some point that I'm missing. And
having spent like 2 hours trying to get the semantics right for that, I'd be
happy to switch it back to use the refcounted ptr :)

[tommi, 2015-10-23 12:56:05]

The CQ bit was checked by tommi@webrtc.org

[tommi, 2015-10-23 12:56:05]

lgtm

[commit-bot: I haz the power, 2015-10-23 12:56:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1414053003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1414053003/1

[commit-bot: I haz the power, 2015-10-23 13:01:14]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-23 13:01:23]

Patchset 1 (id:??) landed as
https://crrev.com/27dfe201a55b345c17ca4586a5a5a3a9ab245ee9
Cr-Commit-Position: refs/heads/master@{#10386}