Remove Gamepad Extensions flag

The extensions are now enabled along with the WebVR flag.

There is still a separate Blink runtime feature (renamed to
WebVRGamepadSupport) for clarity in the IDL files, especially until
WebXR moves completely off Gamepad (

Bug: 915304
Test: blink/web_tests/http/tests/origin_trials/webexposed/{vr|xr}/
Change-Id: I8e5893bbb8de089dee8cf574c4bf4bba2206e9ef
Reviewed-by: Pavel Feldman <>
Reviewed-by: Brandon Jones <>
Reviewed-by: Bill Orr <>
Commit-Queue: David Dorwin <>
Cr-Commit-Position: refs/heads/master@{#622219}
13 files changed