bluetooth: Change GetInquiryTxPower and GetInquiryRSSI to return optional.

device/bluetooth/test/mock_bluetooth_device.h

Index: device/bluetooth/test/mock_bluetooth_device.h
diff --git a/device/bluetooth/test/mock_bluetooth_device.h b/device/bluetooth/test/mock_bluetooth_device.h
index a7ed03ab37cecceb288d769fda128b199e88c0e1..b70bfe584fe0034f6ce61a066268ce4648dcd219 100644
--- a/device/bluetooth/test/mock_bluetooth_device.h
+++ b/device/bluetooth/test/mock_bluetooth_device.h
@@ -52,8 +52,8 @@ class MockBluetoothDevice : public BluetoothDevice {
   MOCK_CONST_METHOD0(IsConnectable, bool());
   MOCK_CONST_METHOD0(IsConnecting, bool());
   MOCK_CONST_METHOD0(GetUUIDs, UUIDList());
-  MOCK_CONST_METHOD0(GetInquiryRSSI, int16_t());
-  MOCK_CONST_METHOD0(GetInquiryTxPower, int16_t());
+  MOCK_CONST_METHOD0(GetInquiryRSSI, base::Optional<int8_t>());
+  MOCK_CONST_METHOD0(GetInquiryTxPower, base::Optional<int8_t>());
   MOCK_CONST_METHOD0(ExpectingPinCode, bool());
   MOCK_CONST_METHOD0(ExpectingPasskey, bool());
   MOCK_CONST_METHOD0(ExpectingConfirmation, bool());