Fix race condition in gamepad that prevents it to work without a rAF loop

Fix race condition in gamepad that prevents it to work without a rAF loop

GamepadSharedMemoryReader checks for user gesture. But it only does that
when someone actually calls SampleGamepads, so in case that does not
happen periodically we will miss it. The browser side already has
the logic to detect user interaction so let's rely on that.

BUG=380870
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=277102

[bajones, 2014-06-04 22:00:58]

Non-owner LGTM. Thanks for catching this edge case. I think most people will use
the API in a loop anyway but there's no reason this shouldn't work.

[kbalazs, 2014-06-13 00:12:02]

Can I get an owner review, please.

[jam, 2014-06-13 17:06:53]

lgtm

[kbalazs, 2014-06-13 17:19:02]

The CQ bit was checked by b.kelemen@samsung.com

[commit-bot: I haz the power, 2014-06-13 17:20:40]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/b.kelemen@samsung.com/316013007/1

[commit-bot: I haz the power, 2014-06-13 20:41:10]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  android_dbg_triggered_tests on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg_triggered...)

[commit-bot: I haz the power, 2014-06-13 22:06:15]

Change committed as 277102