serial: Enable alternative port enumeration method by default

This change enables the kUseSerialBusEnumerator feature by default,
enabling an alternative method for performing the initial enumeration
of serial ports which seems to include a few ports using older drivers
that don't show up when using the more modern method.

This still does not fix connection and disconnection events for such
devices. If there are no reports of missing ports with this flag enabled
it will be removed in M-89.

Bug: 1119497
Change-Id: I42776a7edb737d69c52e9fb1f646a9ed60f1a668
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2437490
Auto-Submit: Reilly Grant <reillyg@chromium.org>
Commit-Queue: James Hollyer <jameshollyer@chromium.org>
Reviewed-by: James Hollyer <jameshollyer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811795}

services/device/public/cpp/device_features.cc

@@ -25,10 +25,10 @@ const base::Feature kMacCoreLocationImplementation{
 
 #if defined(OS_WIN)
 // Switches from enumerating serial ports using GUID_DEVINTERFACE_SERIALPORT to
-// GUID_DEVINTERFACE_SERENUM_BUS_ENUMERATOR. This is an experimental solution to
+// GUID_DEVINTERFACE_SERENUM_BUS_ENUMERATOR. This is an partial solution to
 // https://crbug.com/1119497.
 const base::Feature kUseSerialBusEnumerator{"UseSerialBusEnumerator",
-                                            base::FEATURE_DISABLED_BY_DEFAULT};
+                                            base::FEATURE_ENABLED_BY_DEFAULT};
 #endif  // defined(OS_WIN)
 
 }  // namespace features