Migrate chrome.bluetooth API backend to use device::BluetoothDiscoverySession.

device/bluetooth/test/mock_bluetooth_adapter.cc

Index: device/bluetooth/test/mock_bluetooth_adapter.cc
diff --git a/device/bluetooth/test/mock_bluetooth_adapter.cc b/device/bluetooth/test/mock_bluetooth_adapter.cc
index 5848db3f16416b19b5a8b6ed724e184109d3ba88..9938cc373286335e173cf155c16d89939e09c968 100644
--- a/device/bluetooth/test/mock_bluetooth_adapter.cc
+++ b/device/bluetooth/test/mock_bluetooth_adapter.cc
@@ -14,4 +14,12 @@ MockBluetoothAdapter::MockBluetoothAdapter() {
 
 MockBluetoothAdapter::~MockBluetoothAdapter() {}
 
+void MockBluetoothAdapter::AddDiscoverySession(
+    const base::Closure& callback,
+    const ErrorCallback& error_callback) {}
+
+void MockBluetoothAdapter::RemoveDiscoverySession(
+    const base::Closure& callback,
+    const ErrorCallback& error_callback) {}
+
 }  // namespace device