Add Device Policy Handler for Bluetooth, and allow disabling the Bluetooth adapter on Chrome OS

device/bluetooth/bluetooth_adapter_bluez.cc

Index: device/bluetooth/bluetooth_adapter_bluez.cc
diff --git a/device/bluetooth/bluetooth_adapter_bluez.cc b/device/bluetooth/bluetooth_adapter_bluez.cc
index 4424b0229d667befdb432cfc2b17dc4dd88d3040..a310e1dd1b667fc05e58660b95ee2231148c983d 100644
--- a/device/bluetooth/bluetooth_adapter_bluez.cc
+++ b/device/bluetooth/bluetooth_adapter_bluez.cc
@@ -153,6 +153,7 @@ BluetoothAdapterBlueZ::BluetoothAdapterBlueZ(const InitCallback& init_callback)
     : init_callback_(init_callback),
       initialized_(false),
       dbus_is_shutdown_(false),
+      is_disabled_(false),

[ortuno, 2016/04/13 21:12:21]

You never set this to true on non-chromeos platforms. This results in disabling
bluetooth for all linux users D:

[Ivan Šandrk, 2016/04/14 18:08:48]

Removed it for non-chromeos platforms.

       num_discovery_sessions_(0),
       discovery_request_pending_(false),
       weak_ptr_factory_(this) {
@@ -254,7 +255,15 @@ bool BluetoothAdapterBlueZ::IsInitialized() const {
 }
 
 bool BluetoothAdapterBlueZ::IsPresent() const {
-  return !dbus_is_shutdown_ && !object_path_.value().empty();
+  return !is_disabled_ && !dbus_is_shutdown_ && !object_path_.value().empty();
+}
+
+void BluetoothAdapterBlueZ::SetDisabled(bool disabled) {
+  if (disabled) {
+    SetPowered(false, base::Bind(&base::DoNothing),

[ortuno, 2016/04/13 21:12:21]

Does powering off the adapter remove already discovered devices? It's not clear
that users of the adapter will no longer be able to use device they've already
discovered.

[Ivan Šandrk, 2016/04/14 18:08:48]

https://code.google.com/p/chromium/codesearch#chromium/src/device/bluetooth/b...

Methods tolerate a shutdown scenario where BluetoothAdapterBlueZ::Shutdown
causes IsPresent to return false just before the dbus system is shutdown but
while references to the BluetoothAdapterBlueZ object still exists.

So I'm assuming it's fine because I also use IsPresent. Would like to hear what
you think about this :)

[scheib, 2016/04/14 21:41:10]

But you're not calling ::Shutdown which removes those devices.

[Ivan Šandrk, 2016/04/15 17:32:06]

Should I then copy some of the functionality that Shutdown has? Or that wouldn't
work?

+               base::Bind(&base::DoNothing));
+  }
+  is_disabled_ = disabled;
 }
 
 bool BluetoothAdapterBlueZ::IsPowered() const {