device/bluetooth: Move GATT observer methods to BluetoothAdapter::Observer.

device/bluetooth/bluetooth_device_mac.h

Index: device/bluetooth/bluetooth_device_mac.h
diff --git a/device/bluetooth/bluetooth_device_mac.h b/device/bluetooth/bluetooth_device_mac.h
index 68380c200a99f78c3e4acb529835c1d315c34a51..b10757335bc8062aee35b94190b79fd83140a999 100644
--- a/device/bluetooth/bluetooth_device_mac.h
+++ b/device/bluetooth/bluetooth_device_mac.h
@@ -24,10 +24,6 @@ class BluetoothDeviceMac : public BluetoothDevice {
   virtual ~BluetoothDeviceMac();
 
   // BluetoothDevice override
-  virtual void AddObserver(
-      device::BluetoothDevice::Observer* observer) OVERRIDE;
-  virtual void RemoveObserver(
-      device::BluetoothDevice::Observer* observer) OVERRIDE;
   virtual uint32 GetBluetoothClass() const OVERRIDE;
   virtual std::string GetAddress() const OVERRIDE;
   virtual VendorIDSource GetVendorIDSource() const OVERRIDE;
@@ -89,9 +85,6 @@ class BluetoothDeviceMac : public BluetoothDevice {
   int GetHostTransmitPower(
       BluetoothHCITransmitPowerLevelType power_level_type) const;
 
-  // List of observers interested in event notifications from us.
-  ObserverList<Observer> observers_;
-
   base::scoped_nsobject<IOBluetoothDevice> device_;
 
   DISALLOW_COPY_AND_ASSIGN(BluetoothDeviceMac);