Add DBus plumbing and tests for sending devices with ATT read/writes.

device/bluetooth/dbus/fake_bluetooth_gatt_characteristic_service_provider.cc

Index: device/bluetooth/dbus/fake_bluetooth_gatt_characteristic_service_provider.cc
diff --git a/device/bluetooth/dbus/fake_bluetooth_gatt_characteristic_service_provider.cc b/device/bluetooth/dbus/fake_bluetooth_gatt_characteristic_service_provider.cc
index 7b80de0a0bf875bf364bfbe1e0dbfebe5075adfd..cbc240dc5aa0517c8548fdb05e59508fa46530d3 100644
--- a/device/bluetooth/dbus/fake_bluetooth_gatt_characteristic_service_provider.cc
+++ b/device/bluetooth/dbus/fake_bluetooth_gatt_characteristic_service_provider.cc
@@ -113,6 +113,7 @@ void FakeBluetoothGattCharacteristicServiceProvider::SendValueChanged(
 }
 
 void FakeBluetoothGattCharacteristicServiceProvider::GetValue(
+    const dbus::ObjectPath& device_path,
     const device::BluetoothLocalGattService::Delegate::ValueCallback& callback,
     const device::BluetoothLocalGattService::Delegate::ErrorCallback&
         error_callback) {
@@ -136,10 +137,11 @@ void FakeBluetoothGattCharacteristicServiceProvider::GetValue(
 
   // Pass on to the delegate.
   DCHECK(delegate_);
-  delegate_->GetValue(callback, error_callback);
+  delegate_->GetValue(device_path, callback, error_callback);
 }
 
 void FakeBluetoothGattCharacteristicServiceProvider::SetValue(
+    const dbus::ObjectPath& device_path,
     const std::vector<uint8_t>& value,
     const base::Closure& callback,
     const device::BluetoothLocalGattService::Delegate::ErrorCallback&
@@ -164,7 +166,7 @@ void FakeBluetoothGattCharacteristicServiceProvider::SetValue(
 
   // Pass on to the delegate.
   DCHECK(delegate_);
-  delegate_->SetValue(value, callback, error_callback);
+  delegate_->SetValue(device_path, value, callback, error_callback);
 }
 
 bool FakeBluetoothGattCharacteristicServiceProvider::NotificationsChange(