Revise gamepad interface

Revise gamepad interface

Per API review, revision to gamepad interface. Still in _dev for now, will move to stable as separate change once we're happy with the interface.

Change summary:
- renames of various fields, and main function in idl per discussion
- timestamp to double, connected to PP_Bool
- remove #pragma pack in header, now copied member-by-member
- update examples

One complication was in removing the #pragma pack. Copying by member in webkit/plugins/ppapi/ppapi_plugin_instance.cc avoids the need to keep webkit and pepper in sync and exactly the same layout (a good thing).

However, when the native_client ppapi proxy is going between 32 and 64 the data structure ends up being a different size due to padding (all the fields are teh same sizes though). To workaround this, I added padding fields, and assert_sizes to confirm the sizes are the same on both "sides". This is similar to how PP_Point, input events, etc. get rpc'd, but perhaps there's a better way.

BUG=112879
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=124375

[brettw, 2012-02-27 17:44:20]

lgtm

https://chromiumcodereview.appspot.com/9405033/diff/12001/ppapi/api/dev/ppb_g...
File ppapi/api/dev/ppb_gamepad_dev.idl (right):

https://chromiumcodereview.appspot.com/9405033/diff/12001/ppapi/api/dev/ppb_g...
ppapi/api/dev/ppb_gamepad_dev.idl:86: [version=0.1,
macro="PPB_GAMEPAD_DEV_INTERFACE"]
Can you bump the version? (Also at the top with the "label Chrome").

https://chromiumcodereview.appspot.com/9405033/diff/12001/webkit/plugins/ppap...
File webkit/plugins/ppapi/ppapi_plugin_instance.cc (right):

https://chromiumcodereview.appspot.com/9405033/diff/12001/webkit/plugins/ppap...
webkit/plugins/ppapi/ppapi_plugin_instance.cc:1349: WebKit::WebGamepads
webkit_data;
I know it was already here, but can you move this code to event_conversion.cc?
This file is so large.

[scottmg, 2012-02-27 21:29:48]

Thanks Brett.

https://chromiumcodereview.appspot.com/9405033/diff/12001/ppapi/api/dev/ppb_g...
File ppapi/api/dev/ppb_gamepad_dev.idl (right):

https://chromiumcodereview.appspot.com/9405033/diff/12001/ppapi/api/dev/ppb_g...
ppapi/api/dev/ppb_gamepad_dev.idl:86: [version=0.1,
macro="PPB_GAMEPAD_DEV_INTERFACE"]
On 2012/02/27 17:44:20, brettw wrote:
> Can you bump the version? (Also at the top with the "label Chrome").

Done.

https://chromiumcodereview.appspot.com/9405033/diff/12001/webkit/plugins/ppap...
File webkit/plugins/ppapi/ppapi_plugin_instance.cc (right):

https://chromiumcodereview.appspot.com/9405033/diff/12001/webkit/plugins/ppap...
webkit/plugins/ppapi/ppapi_plugin_instance.cc:1349: WebKit::WebGamepads
webkit_data;
On 2012/02/27 17:44:20, brettw wrote:
> I know it was already here, but can you move this code to event_conversion.cc?
> This file is so large.

Done.

[scottmg, 2012-02-28 18:09:18]

+noelallen for OWNERS on native_client_sdk/src/examples/gamepad/gamepad.cc

[scottmg, 2012-02-29 23:02:49]

+erikkay, looks like noel's out, could I get you to stamp for OWNERS, just for
cosmetic changes in native_client_sdk/src/examples/gamepad/gamepad.cc

[noelallen_use_chromium, 2012-02-29 23:09:16]

https://chromiumcodereview.appspot.com/9405033/diff/20001/ppapi/api/dev/ppb_g...
File ppapi/api/dev/ppb_gamepad_dev.idl (left):

https://chromiumcodereview.appspot.com/9405033/diff/20001/ppapi/api/dev/ppb_g...
ppapi/api/dev/ppb_gamepad_dev.idl:91: void SampleGamepads(
Keep this but add:
[deprecate=0.2] void SampleGamepads()...
[version=0.2] void Sample()...

https://chromiumcodereview.appspot.com/9405033/diff/20001/ppapi/api/dev/ppb_g...
File ppapi/api/dev/ppb_gamepad_dev.idl (right):

https://chromiumcodereview.appspot.com/9405033/diff/20001/ppapi/api/dev/ppb_g...
ppapi/api/dev/ppb_gamepad_dev.idl:12: M19 = 0.2
You should be reving the interface, not deleting the old one.  This is losing
the change history.

In theory you should keep PP_GamepadData_Dev unmodified, create a new struct
call PP_GamepadSampleData and then rev the interface as shown bellow.

https://chromiumcodereview.appspot.com/9405033/diff/20001/ppapi/api/dev/ppb_g...
ppapi/api/dev/ppb_gamepad_dev.idl:86: [version=0.2,
macro="PPB_GAMEPAD_DEV_INTERFACE"]
This interface started it's existance at 0.1.  it changed at 0.2.  Losing the
history this way can make transitioning painful.

My recommendation is to do your cleanup as you transition this from 'Dev'.  You
can prune to your heart's content there since the interface name changes and
basically becomes completely unusable.

[scottmg, 2012-02-29 23:15:47]

On 2012/02/29 23:09:16, noelallen wrote:
>
https://chromiumcodereview.appspot.com/9405033/diff/20001/ppapi/api/dev/ppb_g...
> File ppapi/api/dev/ppb_gamepad_dev.idl (left):
> 
>
https://chromiumcodereview.appspot.com/9405033/diff/20001/ppapi/api/dev/ppb_g...
> ppapi/api/dev/ppb_gamepad_dev.idl:91: void SampleGamepads(
> Keep this but add:
> [deprecate=0.2] void SampleGamepads()...
> [version=0.2] void Sample()...
> 
>
https://chromiumcodereview.appspot.com/9405033/diff/20001/ppapi/api/dev/ppb_g...
> File ppapi/api/dev/ppb_gamepad_dev.idl (right):
> 
>
https://chromiumcodereview.appspot.com/9405033/diff/20001/ppapi/api/dev/ppb_g...
> ppapi/api/dev/ppb_gamepad_dev.idl:12: M19 = 0.2
> You should be reving the interface, not deleting the old one.  This is losing
> the change history.
> 
> In theory you should keep PP_GamepadData_Dev unmodified, create a new struct
> call PP_GamepadSampleData and then rev the interface as shown bellow.
> 
>
https://chromiumcodereview.appspot.com/9405033/diff/20001/ppapi/api/dev/ppb_g...
> ppapi/api/dev/ppb_gamepad_dev.idl:86: [version=0.2,
> macro="PPB_GAMEPAD_DEV_INTERFACE"]
> This interface started it's existance at 0.1.  it changed at 0.2.  Losing the
> history this way can make transitioning painful.
> 
> My recommendation is to do your cleanup as you transition this from 'Dev'. 
You
> can prune to your heart's content there since the interface name changes and
> basically becomes completely unusable.

Ah, OK. I thought the change from 18->19 meant it was OK to break dev
interfaces.

So just to confirm, you're saying I should leave the 18 _dev interface as it
was, and make the changes to the "new" interface in stable so the renames don't
break anything?

OK, I'll rework this change to roll in the move to stable then.

[noelallen1, 2012-02-29 23:24:21]

Since this change is really pre-move cleanup, and since the M18 version is going
away as this goes from Dev to Stable, I think getting rid of the extras now
makes sense.

So check this in as-is, and just remember to bump the version number from 0.2 to
1.0 when you rename and move to stable.

LGTM

[commit-bot: I haz the power, 2012-02-29 23:41:07]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/scottmg@chromium.org/9405033/25002

[commit-bot: I haz the power, 2012-03-01 06:44:53]

Change committed as 124375