Fixed first step of scrolling not applying

Fixed first step of scrolling not applying

I fixed the first step of scrolling not applying when switching from one slave
mouse device to another. This bug was happening because the Xinput2 event
XIDeviceChangedEvent is used for two different reasons, a device's properties
changing and the current slave device being switched. This code checks that the
reason field is set to XIDeviceChange (rather than XISlaveSwitch).

BUG=593453
Review URL: https://codereview.chromium.org/1883853002

Cr-Commit-Position: refs/heads/master@{#388182}
(cherry picked from commit 47c6f3e7252ece9b52e5b86d40944e66442ea7aa)

Committed: https://chromium.googlesource.com/chromium/src/+/62bcee1fab7fde7b93fe299f13f168bb73812b46

[bokan, 2016-04-27 13:48:59]

Description was changed from

==========
Fixed first step of scrolling not applying

I fixed the first step of scrolling not applying when switching from one slave
mouse device to another. This bug was happening because the Xinput2 event
XIDeviceChangedEvent is used for two different reasons, a device's properties
changing and the current slave device being switched. This code checks that the
reason field is set to XIDeviceChange (rather than XISlaveSwitch).

BUG=593453

Review URL: https://codereview.chromium.org/1883853002

Cr-Commit-Position: refs/heads/master@{#388182}
(cherry picked from commit 47c6f3e7252ece9b52e5b86d40944e66442ea7aa)
==========

to

==========
Fixed first step of scrolling not applying

I fixed the first step of scrolling not applying when switching from one slave
mouse device to another. This bug was happening because the Xinput2 event
XIDeviceChangedEvent is used for two different reasons, a device's properties
changing and the current slave device being switched. This code checks that the
reason field is set to XIDeviceChange (rather than XISlaveSwitch).

BUG=593453

Review URL: https://codereview.chromium.org/1883853002

Cr-Commit-Position: refs/heads/master@{#388182}
(cherry picked from commit 47c6f3e7252ece9b52e5b86d40944e66442ea7aa)

Committed:
https://chromium.googlesource.com/chromium/src/+/62bcee1fab7fde7b93fe299f13f1...
==========

[bokan, 2016-04-27 13:49:00]

Committed patchset #1 (id:1) manually as
62bcee1fab7fde7b93fe299f13f168bb73812b46.