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

device/bluetooth/bluetooth_adapter_bluez.h

Index: device/bluetooth/bluetooth_adapter_bluez.h
diff --git a/device/bluetooth/bluetooth_adapter_bluez.h b/device/bluetooth/bluetooth_adapter_bluez.h
index 3d402d4fd1afac5b8da441256531c03e80f63e8d..deba2df891f59b75559cbe26f969330e85363e4c 100644
--- a/device/bluetooth/bluetooth_adapter_bluez.h
+++ b/device/bluetooth/bluetooth_adapter_bluez.h
@@ -86,6 +86,7 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothAdapterBlueZ
                const ErrorCallback& error_callback) override;
   bool IsInitialized() const override;
   bool IsPresent() const override;
+  void SetDisabled(bool disabled) override;
   bool IsPowered() const override;
   void SetPowered(bool powered,
                   const base::Closure& callback,
@@ -346,6 +347,10 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothAdapterBlueZ
   // Set in |Shutdown()|, makes IsPresent()| return false.
   bool dbus_is_shutdown_;
 
+  // Set in |SetDisabled()|, makes |IsPresent()| return false
+  // (just disables the interface, doesn't actually shut it down).

[Andrew T Wilson (Slow), 2016/04/13 13:55:11]

One question - why did we decide to change the value of IsPresent() rather than
asking callers to call IsDisabled() to check whether it's disabled?

[Ivan Šandrk, 2016/04/13 17:19:04]

It seemed like a simpler solution since no code changes elsewhere were needed,
and it also imposes less on users of the Bluetooth adapter (maybe someone
forgets to call IsDisabled together with IsPresent). But it's not the cleanest
solution, that's true.

+  bool is_disabled_;
+
   // Number of discovery sessions that have been added.
   int num_discovery_sessions_;