Refactor to support default Bluetooth pairing delegate

chromeos/dbus/fake_bluetooth_agent_manager_client.cc

Index: chromeos/dbus/fake_bluetooth_agent_manager_client.cc
diff --git a/chromeos/dbus/fake_bluetooth_agent_manager_client.cc b/chromeos/dbus/fake_bluetooth_agent_manager_client.cc
index 2672ad56cbd6360683e74ca8617f8726aefa91ef..b2bdf964cc4acd25fc8cc35ed28fe3f3503a284a 100644
--- a/chromeos/dbus/fake_bluetooth_agent_manager_client.cc
+++ b/chromeos/dbus/fake_bluetooth_agent_manager_client.cc
@@ -45,8 +45,11 @@ void FakeBluetoothAgentManagerClient::UnregisterAgent(
     const base::Closure& callback,
     const ErrorCallback& error_callback) {
   VLOG(1) << "UnregisterAgent: " << agent_path.value();
-  if (service_provider_ != NULL) {
-    error_callback.Run(bluetooth_agent_manager::kErrorInvalidArguments,
+  if (service_provider_ == NULL) {
+    error_callback.Run(bluetooth_agent_manager::kErrorDoesNotExist,
+                       "No agent registered");
+  } else if (service_provider_->object_path_ != agent_path) {
+    error_callback.Run(bluetooth_agent_manager::kErrorDoesNotExist,
                        "Agent still registered");
   } else {
     callback.Run();