Disable WebUSB detector logic on Windows.

Disable WebUSB detector logic on Windows.

Initializing the WebUSB device detector logic causes the USB subsystem
to attempt to fully enumerate the system's USB bus. This has been found
to cause jank and hangs on Chrome's FILE thread on Windows. Disabling
this component of WebUSB while the issue is investigated.

WebUSB will continue to function but this change will prevent the issue
from impacting users who do not visit sites using it.

BUG=656702
TEST=Verified USB subsystem is not initialized on startup on Windows by
checking chrome://device-log. Verified still initialized on Linux.

Review-Url: https://codereview.chromium.org/2422403003
Cr-Commit-Position: refs/heads/master@{#425867}
(cherry picked from commit dfd32df76aea1a2d4f1aad69c74ded742a2ac69b)

Committed: https://chromium.googlesource.com/chromium/src/+/2ac51a5dd890c0944f4d689792319426fb5f9850

[Reilly Grant (use Gerrit), 2016-10-18 22:21:20]

Description was changed from

==========
Disable WebUSB detector logic on Windows.

Initializing the WebUSB device detector logic causes the USB subsystem
to attempt to fully enumerate the system's USB bus. This has been found
to cause jank and hangs on Chrome's FILE thread on Windows. Disabling
this component of WebUSB while the issue is investigated.

WebUSB will continue to function but this change will prevent the issue
from impacting users who do not visit sites using it.

BUG=656702
TEST=Verified USB subsystem is not initialized on startup on Windows by
checking chrome://device-log. Verified still initialized on Linux.

Review-Url: https://codereview.chromium.org/2422403003
Cr-Commit-Position: refs/heads/master@{#425867}
(cherry picked from commit dfd32df76aea1a2d4f1aad69c74ded742a2ac69b)
==========

to

==========
Disable WebUSB detector logic on Windows.

Initializing the WebUSB device detector logic causes the USB subsystem
to attempt to fully enumerate the system's USB bus. This has been found
to cause jank and hangs on Chrome's FILE thread on Windows. Disabling
this component of WebUSB while the issue is investigated.

WebUSB will continue to function but this change will prevent the issue
from impacting users who do not visit sites using it.

BUG=656702
TEST=Verified USB subsystem is not initialized on startup on Windows by
checking chrome://device-log. Verified still initialized on Linux.

Review-Url: https://codereview.chromium.org/2422403003
Cr-Commit-Position: refs/heads/master@{#425867}
(cherry picked from commit dfd32df76aea1a2d4f1aad69c74ded742a2ac69b)

Committed:
https://chromium.googlesource.com/chromium/src/+/2ac51a5dd890c0944f4d68979231...
==========

[Reilly Grant (use Gerrit), 2016-10-18 22:21:22]

Committed patchset #1 (id:1) manually as
2ac51a5dd890c0944f4d689792319426fb5f9850.