ozone: Implement PlatformObject<T> for platform-specific objects

ozone: Implement PlatformObject<T> for platform-specific objects

This paves the way for having more than one platform-specific object,
which is necessary for the componentization of ozone.

The plumbing to build objects that depend on the platform is shared
using the PlatformObject<T> template.

Code that wants to build such an object need simply do

  scoped_ptr<MyPlatformSpecificType> my_platform_object =
      PlatformObject<MyPlatformSpecificType>::Create();

We have to generate a couple of source files to make this work:

  - a header file with an enumeration of platforms
  - a (per-component) source file with a static const list of
    constructors for each platform type

This converts the previous object (OzonePlatform) instantiation
to use PlatformObject<>. This should be functionally identical.

BUG=380884
TEST=build aura_builder with "use_ozone=1 chromeos=1", ran egltest
NOTRY=true

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=275460

[rjkroege, 2014-06-04 22:34:29]

lgtm

[vignatti (out of this project), 2014-06-05 17:28:50]

https://codereview.chromium.org/313963007/diff/30001/ui/ozone/platform_select...
File ui/ozone/platform_selection.h (right):

https://codereview.chromium.org/313963007/diff/30001/ui/ozone/platform_select...
ui/ozone/platform_selection.h:9: #include "ui/ozone/platform_list.h"
copy pasta mistake probably? This line has to be removed.

[spang, 2014-06-06 17:00:34]

The CQ bit was checked by spang@chromium.org

[commit-bot: I haz the power, 2014-06-06 17:01:07]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/spang@chromium.org/313963007/50001

[commit-bot: I haz the power, 2014-06-06 17:02:33]

Change committed as 275460

[vignatti (out of this project), 2014-06-06 17:03:01]

https://codereview.chromium.org/313963007/diff/50001/ui/ozone/platform_object.h
File ui/ozone/platform_object.h (right):

https://codereview.chromium.org/313963007/diff/50001/ui/ozone/platform_object...
ui/ozone/platform_object.h:30: };
just like I told you on IRC, PlatformObject being inside ui doesn't work for
objects in a different namespace. What's the plan here?

[spang, 2014-06-06 17:05:09]

https://codereview.chromium.org/313963007/diff/50001/ui/ozone/platform_object.h
File ui/ozone/platform_object.h (right):

https://codereview.chromium.org/313963007/diff/50001/ui/ozone/platform_object...
ui/ozone/platform_object.h:30: };
On 2014/06/06 17:03:01, vignatti wrote:
> just like I told you on IRC, PlatformObject being inside ui doesn't work for
> objects in a different namespace. What's the plan here?

Your problem was just a bug in the script. Should be fixed in landed patch.

[vignatti (out of this project), 2014-06-06 18:19:23]

On 2014/06/06 17:05:09, spang wrote:
>
https://codereview.chromium.org/313963007/diff/50001/ui/ozone/platform_object.h
> File ui/ozone/platform_object.h (right):
> 
>
https://codereview.chromium.org/313963007/diff/50001/ui/ozone/platform_object...
> ui/ozone/platform_object.h:30: };
> On 2014/06/06 17:03:01, vignatti wrote:
> > just like I told you on IRC, PlatformObject being inside ui doesn't work for
> > objects in a different namespace. What's the plan here?
> 
> Your problem was just a bug in the script. Should be fixed in landed patch.

true. And I was trying in my system the old patchset, my bad. I've tested and
everything is working like a charm. Thank you.