Fix broken normalization of some HID axes on OSX

Fix broken normalization of some HID axes on OSX

The OUYA and Nvidia Shield controllers report axes with a logical
range of -1 to 0. The integer values returned by HID manager for these
axes range from 0 to 65535. Without treating these logical ranges
as unsigned, the normalization calculation yields incorrect results.

Post-normalization, these special axes are also opposite of how the
gamepad code expects them (1 to -1 instead of -1 to 1). This CL swaps
logical min and max for these axes to invert the result of normalization.

R=bajones@chromium.org

BUG=608170
TEST=HTML5 Gamepad API test with OUYA or Nvidia Shield controller

Committed: https://crrev.com/7dac9dec172d28199da24e3084c6449284f12a90
Cr-Commit-Position: refs/heads/master@{#390866}

[cgutman, 2016-04-30 21:49:32]

This change addresses incorrect normalization on some gamepads on OSX that leads
to normalized values outside the range of -1.0 to 1.0. 

After we address this normalization issue, I can upload a CL with standard
mappings for Nvidia Shield and OUYA controllers on OSX.

[bajones, 2016-04-30 23:09:17]

On 2016/04/30 21:49:32, cgutman wrote:
> This change addresses incorrect normalization on some gamepads on OSX that
leads
> to normalized values outside the range of -1.0 to 1.0. 
> 
> After we address this normalization issue, I can upload a CL with standard
> mappings for Nvidia Shield and OUYA controllers on OSX.

LGTM. Thanks for making this bit of logic more robust.

[bajones, 2016-04-30 23:09:29]

The CQ bit was checked by bajones@chromium.org

[commit-bot: I haz the power, 2016-04-30 23:09:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1939613003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1939613003/1

[commit-bot: I haz the power, 2016-05-01 00:01:27]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-05-01 00:02:55]

Description was changed from

==========
Fix broken normalization of some HID axes on OSX

The OUYA and Nvidia Shield controllers report axes with a logical
range of -1 to 0. The integer values returned by HID manager for these
axes range from 0 to 65535. Without treating these logical ranges
as unsigned, the normalization calculation yields incorrect results.

Post-normalization, these special axes are also opposite of how the
gamepad code expects them (1 to -1 instead of -1 to 1). This CL swaps
logical min and max for these axes to invert the result of normalization.

R=bajones@chromium.org

BUG=608170
TEST=HTML5 Gamepad API test with OUYA or Nvidia Shield controller
==========

to

==========
Fix broken normalization of some HID axes on OSX

The OUYA and Nvidia Shield controllers report axes with a logical
range of -1 to 0. The integer values returned by HID manager for these
axes range from 0 to 65535. Without treating these logical ranges
as unsigned, the normalization calculation yields incorrect results.

Post-normalization, these special axes are also opposite of how the
gamepad code expects them (1 to -1 instead of -1 to 1). This CL swaps
logical min and max for these axes to invert the result of normalization.

R=bajones@chromium.org

BUG=608170
TEST=HTML5 Gamepad API test with OUYA or Nvidia Shield controller

Committed: https://crrev.com/7dac9dec172d28199da24e3084c6449284f12a90
Cr-Commit-Position: refs/heads/master@{#390866}
==========

[commit-bot: I haz the power, 2016-05-01 00:02:56]

Patchset 1 (id:??) landed as
https://crrev.com/7dac9dec172d28199da24e3084c6449284f12a90
Cr-Commit-Position: refs/heads/master@{#390866}