Delayload bluetooth imports on Windows.

Delayload bluetooth imports on Windows.

Some systems (e.g., Windows Server 2012) do not have a bluetooth stack, so the corresponding dll (bthprops.cpl) isn't present. If neither delayload nor explicit runtime binding is used, then binaries linking in the device_bluetooth target will fail to load on such systems.

BUG=135470
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=171353

[grt (UTC plus 2), 2012-12-04 15:21:30]

robertshield: please review the CL description and content for Windows-fu
bryeung: please provider your OWNERShip blessing if you consent to this change

[grt (UTC plus 2), 2012-12-04 15:28:05]

Robert just convinced me that it's more safer if I put in the detection code now
so that this half-way change doesn't somehow end up in production. I'll send out
a revised CR in a bit. Thanks.

[bryeung, 2012-12-04 15:41:39]

Happy to give OWNERS blessing after Youngki has reviewed (he's actually the one
implementing the Windows code).

[grt (UTC plus 2), 2012-12-04 18:48:20]

Okay, ready for review. Youngki: I left a TODO for you in the code since this
seems to be a work in progress.

[robertshield, 2012-12-04 19:00:54]

lgtm

[youngki, 2012-12-05 02:33:08]

lgtm 

Thanks for the CL. I am actually working on creating a dedicated thread to
perform all the bluetooth windows calls
(https://chromiumcodereview.appspot.com/11411130/) so I will make sure to call
HasBluetoothStack() in that thread and invalidate the instance of this class if
that returns false.

[bryeung, 2012-12-05 13:58:44]

lgtm

[commit-bot: I haz the power, 2012-12-05 19:53:48]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/grt@chromium.org/11299332/6001

[commit-bot: I haz the power, 2012-12-05 23:28:03]

Change committed as 171353