[Ozone-DRI] Adding ScanoutBuffer interface

[Ozone-DRI] Adding ScanoutBuffer interface

First step in transitioning HardwareDisplayController to take in buffers rather
than surfaces. ScanoutBuffer defines the minimal interface required by HDC for
modesetting and page-flipping.

BUG=none
NOTRY=true

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=284115

[dnicoara, 2014-07-18 00:06:25]

PTAL

[alexst (slow to review), 2014-07-18 14:09:24]

https://codereview.chromium.org/399213005/diff/20001/ui/ozone/platform/dri/sc...
File ui/ozone/platform/dri/scanout_buffer.h (right):

https://codereview.chromium.org/399213005/diff/20001/ui/ozone/platform/dri/sc...
ui/ozone/platform/dri/scanout_buffer.h:16: class ScanoutBuffer : public
NativePixmap {
Any particular reason you chose to inherit here? In this CL, it doesn't look
like it's used at all.

Albert is moving NativePixmap outside of ozone to be a more general purpose
object as well, btw.

[dnicoara, 2014-07-18 14:22:14]

https://codereview.chromium.org/399213005/diff/20001/ui/ozone/platform/dri/sc...
File ui/ozone/platform/dri/scanout_buffer.h (right):

https://codereview.chromium.org/399213005/diff/20001/ui/ozone/platform/dri/sc...
ui/ozone/platform/dri/scanout_buffer.h:16: class ScanoutBuffer : public
NativePixmap {
On 2014/07/18 14:09:24, alexst wrote:
> Any particular reason you chose to inherit here? In this CL, it doesn't look
> like it's used at all.
> 
> Albert is moving NativePixmap outside of ozone to be a more general purpose
> object as well, btw.

Modifying HDC directly requires lots of other changes so I wanted to split the
change in multiple smaller CLs.

The overall idea is that:

1) HDC will take in a list of OverlayPlanes. I'll make a small change such that
OverlayPlanes carries a scoped_refptr<ScanoutBuffer>.
2) ScanoutSurface will dissapear.
3) DriSurface and DriSurfaceAdapter will meld together. They will carry 2
scoped_refptr<DriBuffer> which will be passed in to HDC on SchedulePageFlip as
the primary overlay plane.

The reasoning behind this change is: the lifetime of HDC can be shorter or
longer than that of SurfaceOzone{Canvas,EGL}. The scanout buffers need to live
until the last one of these objects is destroyed.

Let me know if anything doesn't make sense. If it makes it clearer, I can upload
the remainder of the changes as one CL.

[dnicoara, 2014-07-18 15:20:25]

I've updated based on our offline discussion. Please take another look.

[alexst (slow to review), 2014-07-18 15:25:44]

lgtm, thank you!

[dnicoara, 2014-07-18 16:03:15]

The CQ bit was checked by dnicoara@chromium.org

[commit-bot: I haz the power, 2014-07-18 16:06:38]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dnicoara@chromium.org/399213005/40001

[commit-bot: I haz the power, 2014-07-18 16:16:20]

Change committed as 284115