VideoCaptureDevice: refactor Client::Buffer into an interface

VideoCaptureDevice: refactor Client::Buffer into an interface

The semantics of VideoCaptureDevice::Client::Buffer do not belong
where they are now [1]. Make it pure virtual and move the implementation
to VCController. Rename the derived class to show its purpose.

This also forces adaptation in StubClient of
web_contents_video_capture...unittest.cc.

[1] https://code.google.com/p/chromium/codesearch#chromium/src/media/video/capture/video_capture_device.h&sq=package:chromium&type=cs&l=176

BUG=440843
Committed: https://crrev.com/6e71c8ac2c81ba7e7ff6342b6c0bffcfce5b7949
Cr-Commit-Position: refs/heads/master@{#317334}

[mcasas, 2015-02-20 02:25:07]

mcasas@chromium.org changed reviewers:
+ emircan@chromium.org, perkj@chromium.org

[mcasas, 2015-02-20 02:25:07]

emircan, perkj@ PTAL

[perkj_chrome, 2015-02-20 08:42:13]

What is the purpose? Will you add another implementation of the buffer? 
If so, lgtm. Otherwise I like the simple approach as is.

https://codereview.chromium.org/941833004/diff/1/content/browser/renderer_hos...
File content/browser/renderer_host/media/video_capture_controller.cc (right):

https://codereview.chromium.org/941833004/diff/1/content/browser/renderer_hos...
content/browser/renderer_host/media/video_capture_controller.cc:43: // Class
coalescing a Client::Buffer interface implementation and a pool buffer
Can you simplify the language in this comment a bit please.

[mcasas, 2015-02-20 15:22:01]

New patchsets have been uploaded after l-g-t-m from perkj@chromium.org

[mcasas, 2015-02-20 15:25:51]

On 2015/02/20 08:42:13, perkj wrote:
> What is the purpose? Will you add another implementation of the buffer? 
> If so, lgtm. Otherwise I like the simple approach as is.
> 

Yes, there is something following up (although might not be
inmediate). http://crrev.com/758833002, in which you are a
reviewer, is part of the cake.

I still feel that VCD::Client::Buffer is best left as an
interface and left to implementors to give its actual
semantics... but this is all post-LGTM discussion.

>
https://codereview.chromium.org/941833004/diff/1/content/browser/renderer_hos...
> File content/browser/renderer_host/media/video_capture_controller.cc (right):
> 
>
https://codereview.chromium.org/941833004/diff/1/content/browser/renderer_hos...
> content/browser/renderer_host/media/video_capture_controller.cc:43: // Class
> coalescing a Client::Buffer interface implementation and a pool buffer
> Can you simplify the language in this comment a bit please.

[mcasas, 2015-02-20 15:26:00]

The CQ bit was checked by mcasas@chromium.org

[commit-bot: I haz the power, 2015-02-20 15:26:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/941833004/20001

[mcasas, 2015-02-20 15:59:06]

https://codereview.chromium.org/941833004/diff/1/content/browser/renderer_hos...
File content/browser/renderer_host/media/video_capture_controller.cc (right):

https://codereview.chromium.org/941833004/diff/1/content/browser/renderer_hos...
content/browser/renderer_host/media/video_capture_controller.cc:43: // Class
coalescing a Client::Buffer interface implementation and a pool buffer
On 2015/02/20 08:42:13, perkj wrote:
> Can you simplify the language in this comment a bit please.

Done.

[commit-bot: I haz the power, 2015-02-20 16:29:41]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-02-20 16:30:20]

Patchset 2 (id:??) landed as
https://crrev.com/6e71c8ac2c81ba7e7ff6342b6c0bffcfce5b7949
Cr-Commit-Position: refs/heads/master@{#317334}