cros: Fix GamepadDeviceLinux calling dbus on a wrong thread

Ensure GamepadDataFetcherManager is created on UI thread so that
GamepadPlatformDataFetcherLinux::Factory is created with UI
thread as expected.

Bug: 962884
Change-Id: I2ff3f70baa8df332b43d080340ec1ffc573b015f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1613376
Reviewed-by: Matt Reynolds <mattreynolds@chromium.org>
Commit-Queue: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#660066}
1 file changed