bluetooth: Make the object path an optional argument for Simulate* methods

This make it easier to write tests while still maintaining the
flexibility of the fakes.

Also gives more descriptive names to the adapter objects paths. This
makes the adapter object paths easier to distinguish from future device,
service, characteristic, and descriptor object paths.

Bug: 870192
Change-Id: I716809e757ab2ddf4a261fa2105e2224ec982ee1
Reviewed-on: https://chromium-review.googlesource.com/c/1358117Reviewed-by: Ovidio Henriquez <odejesush@chromium.org>
Commit-Queue: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613301}

services/device/bluetooth/bluetooth_system_unittest.cc

@@ -26,8 +26,8 @@
 
 namespace device {
 
-constexpr const char kFooObjectPathStr[] = "fake/hci0";
-constexpr const char kBarObjectPathStr[] = "fake/hci1";
+constexpr const char kDefaultAdapterObjectPathStr[] = "fake/hci0";
+constexpr const char kAlternateAdapterObjectPathStr[] = "fake/hci1";
 
 namespace {
 
@@ -119,11 +119,14 @@ class DEVICE_BLUETOOTH_EXPORT TestBluetoothAdapterClient
     }
   }
 
-  // Low level methods to simulate events and operations.
+  // Low level methods to simulate events and operations. All actions are
+  // performed for `kDefaultAdapterObjectPathStr` unless a different one is
+  // specified.
 
   // Simulates a new adapter with |object_path_str|. Its properties are empty,
   // 0, or false.
-  void SimulateAdapterAdded(const std::string& object_path_str) {
+  void SimulateAdapterAdded(
+      const std::string& object_path_str = kDefaultAdapterObjectPathStr) {
     dbus::ObjectPath object_path(object_path_str);
 
     ObjectPathToProperties::iterator it;
@@ -150,7 +153,8 @@ class DEVICE_BLUETOOTH_EXPORT TestBluetoothAdapterClient
   }
 
   // Simulates the adapter at |object_path_str| being removed.
-  void SimulateAdapterRemoved(const std::string& object_path_str) {
+  void SimulateAdapterRemoved(
+      const std::string& object_path_str = kDefaultAdapterObjectPathStr) {
     dbus::ObjectPath object_path(object_path_str);
 
     // Properties are set to empty, 0, or false right before AdapterRemoved is
@@ -180,8 +184,9 @@ class DEVICE_BLUETOOTH_EXPORT TestBluetoothAdapterClient
 
   // Simulates adapter at |object_path_str| changing its powered state to
   // |powered|.
-  void SimulateAdapterPowerStateChanged(const std::string& object_path_str,
-                                        bool powered) {
+  void SimulateAdapterPowerStateChanged(
+      bool powered,
+      const std::string& object_path_str = kDefaultAdapterObjectPathStr) {
     auto* properties = GetProperties(dbus::ObjectPath(object_path_str));
     properties->powered.ReplaceValue(powered);
 
@@ -192,13 +197,15 @@ class DEVICE_BLUETOOTH_EXPORT TestBluetoothAdapterClient
       properties->discovering.ReplaceValue(false);
   }
 
-  void SetNextSetPoweredResponse(const std::string& object_path_str,
-                                 bool response) {
+  void SetNextSetPoweredResponse(
+      bool response,
+      const std::string& object_path_str = kDefaultAdapterObjectPathStr) {
     GetProperties(dbus::ObjectPath(object_path_str))
         ->SetNextSetPoweredResponse(response);
   }
 
-  size_t GetSetPoweredCallCount(const std::string& object_path_str) {
+  size_t GetSetPoweredCallCount(
+      const std::string& object_path_str = kDefaultAdapterObjectPathStr) {
     auto it = adapter_object_paths_to_properties_.find(
         dbus::ObjectPath(object_path_str));
     DCHECK(it != adapter_object_paths_to_properties_.end());
@@ -206,7 +213,8 @@ class DEVICE_BLUETOOTH_EXPORT TestBluetoothAdapterClient
     return it->second->set_powered_call_count_;
   }
 
-  bool GetLastSetPoweredValue(const std::string& object_path_str) {
+  bool GetLastSetPoweredValue(
+      const std::string& object_path_str = kDefaultAdapterObjectPathStr) {
     return GetProperties(dbus::ObjectPath(object_path_str))
         ->GetLastSetPoweredValue();
   }
@@ -214,14 +222,15 @@ class DEVICE_BLUETOOTH_EXPORT TestBluetoothAdapterClient
   // Simulates adapter at |object_path_str| changing its discovering state to
   // |powered|.
   void SimulateAdapterDiscoveringStateChanged(
-      const std::string& object_path_str,
-      bool discovering) {
+      bool discovering,
+      const std::string& object_path_str = kDefaultAdapterObjectPathStr) {
     GetProperties(dbus::ObjectPath(object_path_str))
         ->discovering.ReplaceValue(discovering);
   }
 
-  void SetNextStartDiscoveryResponse(const std::string& object_path_str,
-                                     bool response) {
+  void SetNextStartDiscoveryResponse(
+      bool response,
+      const std::string& object_path_str = kDefaultAdapterObjectPathStr) {
     dbus::ObjectPath object_path(object_path_str);
 
     auto& next_response =
@@ -230,13 +239,15 @@ class DEVICE_BLUETOOTH_EXPORT TestBluetoothAdapterClient
     next_response = response;
   }
 
-  size_t GetStartDiscoveryCallCount(const std::string& object_path_str) {
+  size_t GetStartDiscoveryCallCount(
+      const std::string& object_path_str = kDefaultAdapterObjectPathStr) {
     dbus::ObjectPath object_path(object_path_str);
     return adapter_object_paths_to_call_counts_[object_path].start_discovery;
   }
 
-  void SetNextStopDiscoveryResponse(const std::string& object_path_str,
-                                    bool response) {
+  void SetNextStopDiscoveryResponse(
+      bool response,
+      const std::string& object_path_str = kDefaultAdapterObjectPathStr) {
     dbus::ObjectPath object_path(object_path_str);
     auto& next_response =
         adapter_object_paths_to_next_responses_[object_path].stop_discovery;
@@ -244,7 +255,8 @@ class DEVICE_BLUETOOTH_EXPORT TestBluetoothAdapterClient
     next_response = response;
   }
 
-  size_t GetStopDiscoveryCallCount(const std::string& object_path_str) {
+  size_t GetStopDiscoveryCallCount(
+      const std::string& object_path_str = kDefaultAdapterObjectPathStr) {
     dbus::ObjectPath object_path(object_path_str);
     return adapter_object_paths_to_call_counts_[object_path].stop_discovery;
   }
@@ -252,9 +264,10 @@ class DEVICE_BLUETOOTH_EXPORT TestBluetoothAdapterClient
   // Helper methods to perform multiple common operations.
 
   // Simultes adding an adapter and it changing its state to powered On.
-  void SimulatePoweredOnAdapter(const std::string& object_path_str) {
+  void SimulatePoweredOnAdapter(
+      const std::string& object_path_str = kDefaultAdapterObjectPathStr) {
     SimulateAdapterAdded(object_path_str);
-    SimulateAdapterPowerStateChanged(object_path_str, true);
+    SimulateAdapterPowerStateChanged(true, object_path_str);
   }
 
   // BluetoothAdapterClient:
@@ -552,7 +565,7 @@ TEST_F(BluetoothSystemTest, State_NoAdapter) {
 
 // Tests that the state is "Off" when the Bluetooth adapter is powered off.
 TEST_F(BluetoothSystemTest, State_PoweredOffAdapter) {
-  test_bluetooth_adapter_client_->SimulateAdapterAdded(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterAdded();
   // Added adapters are Off by default.
 
   auto system = CreateBluetoothSystem();
@@ -564,7 +577,7 @@ TEST_F(BluetoothSystemTest, State_PoweredOffAdapter) {
 
 // Tests that the state is "On" when the Bluetooth adapter is powered on.
 TEST_F(BluetoothSystemTest, State_PoweredOnAdapter) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   auto system = CreateBluetoothSystem();
 
@@ -575,7 +588,7 @@ TEST_F(BluetoothSystemTest, State_PoweredOnAdapter) {
 // Tests that the state changes to On when the adapter turns on and then changes
 // to Off when the adapter turns off.
 TEST_F(BluetoothSystemTest, State_PoweredOnThenOff) {
-  test_bluetooth_adapter_client_->SimulateAdapterAdded(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterAdded();
 
   auto system = CreateBluetoothSystem();
 
@@ -585,8 +598,7 @@ TEST_F(BluetoothSystemTest, State_PoweredOnThenOff) {
   EXPECT_TRUE(on_state_changed_states_.empty());
 
   // Turn adapter on.
-  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(true);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOn, GetStateAndWait(system));
   EXPECT_EQ(StateVector({mojom::BluetoothSystem::State::kPoweredOn}),
@@ -594,8 +606,7 @@ TEST_F(BluetoothSystemTest, State_PoweredOnThenOff) {
   ResetResults();
 
   // Turn adapter off.
-  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(
-      kFooObjectPathStr, false);
+  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(false);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOff,
             GetStateAndWait(system));
@@ -606,7 +617,7 @@ TEST_F(BluetoothSystemTest, State_PoweredOnThenOff) {
 // Tests that the state is updated as expected when removing and re-adding the
 // same adapter.
 TEST_F(BluetoothSystemTest, State_AdapterRemoved) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   auto system = CreateBluetoothSystem();
 
@@ -615,7 +626,7 @@ TEST_F(BluetoothSystemTest, State_AdapterRemoved) {
   EXPECT_TRUE(on_state_changed_states_.empty());
 
   // Remove the adapter. The state should change to Unavailable.
-  test_bluetooth_adapter_client_->SimulateAdapterRemoved(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterRemoved();
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kUnavailable,
             GetStateAndWait(system));
@@ -625,7 +636,7 @@ TEST_F(BluetoothSystemTest, State_AdapterRemoved) {
   ResetResults();
 
   // Add the adapter again; it's off by default.
-  test_bluetooth_adapter_client_->SimulateAdapterAdded(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterAdded();
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOff,
             GetStateAndWait(system));
@@ -637,7 +648,8 @@ TEST_F(BluetoothSystemTest, State_AdapterRemoved) {
 // different adapter.
 TEST_F(BluetoothSystemTest, State_AdapterReplaced) {
   // Start with a powered on adapter.
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(
+      kDefaultAdapterObjectPathStr);
 
   auto system = CreateBluetoothSystem();
 
@@ -645,7 +657,8 @@ TEST_F(BluetoothSystemTest, State_AdapterReplaced) {
   EXPECT_TRUE(on_state_changed_states_.empty());
 
   // Remove the adapter. The state should change to Unavailable.
-  test_bluetooth_adapter_client_->SimulateAdapterRemoved(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterRemoved(
+      kDefaultAdapterObjectPathStr);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kUnavailable,
             GetStateAndWait(system));
@@ -655,7 +668,8 @@ TEST_F(BluetoothSystemTest, State_AdapterReplaced) {
   ResetResults();
 
   // Add a different adapter. It's off by default.
-  test_bluetooth_adapter_client_->SimulateAdapterAdded(kBarObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterAdded(
+      kAlternateAdapterObjectPathStr);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOff,
             GetStateAndWait(system));
@@ -666,23 +680,27 @@ TEST_F(BluetoothSystemTest, State_AdapterReplaced) {
 // Tests that the state is correctly updated when adding and removing multiple
 // adapters.
 TEST_F(BluetoothSystemTest, State_AddAndRemoveMultipleAdapters) {
-  // Start with a powered on "foo" adapter.
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  // Start with a powered on default adapter.
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(
+      kDefaultAdapterObjectPathStr);
 
   auto system = CreateBluetoothSystem();
 
-  // The "foo" adapter is initially powered on.
+  // The default adapter is initially powered on.
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOn, GetStateAndWait(system));
   EXPECT_TRUE(on_state_changed_states_.empty());
 
-  // Add an extra "bar" adapter. The state should not change.
-  test_bluetooth_adapter_client_->SimulateAdapterAdded(kBarObjectPathStr);
+  // Add an alternate adapter. The state should not change.
+  test_bluetooth_adapter_client_->SimulateAdapterAdded(
+      kAlternateAdapterObjectPathStr);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOn, GetStateAndWait(system));
   EXPECT_TRUE(on_state_changed_states_.empty());
 
-  // Remove "foo". We should retrieve the state from "bar".
-  test_bluetooth_adapter_client_->SimulateAdapterRemoved(kFooObjectPathStr);
+  // Remove the default adapter. We should retrieve the state from the
+  // alternate adapter..
+  test_bluetooth_adapter_client_->SimulateAdapterRemoved(
+      kDefaultAdapterObjectPathStr);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOff,
             GetStateAndWait(system));
@@ -690,17 +708,19 @@ TEST_F(BluetoothSystemTest, State_AddAndRemoveMultipleAdapters) {
             on_state_changed_states_);
   ResetResults();
 
-  // Change "bar"'s state to On.
+  // Change the alternate adapter's state to On.
   test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(
-      kBarObjectPathStr, true);
+      true, kAlternateAdapterObjectPathStr);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOn, GetStateAndWait(system));
   EXPECT_EQ(StateVector({mojom::BluetoothSystem::State::kPoweredOn}),
             on_state_changed_states_);
   ResetResults();
 
-  // Add "foo" again. We should still retrieve the state from "bar".
-  test_bluetooth_adapter_client_->SimulateAdapterAdded(kFooObjectPathStr);
+  // Add the default adapter again. We should still retrieve the state from
+  // the alternate adapter.
+  test_bluetooth_adapter_client_->SimulateAdapterAdded(
+      kDefaultAdapterObjectPathStr);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOn, GetStateAndWait(system));
   EXPECT_TRUE(on_state_changed_states_.empty());
@@ -708,31 +728,33 @@ TEST_F(BluetoothSystemTest, State_AddAndRemoveMultipleAdapters) {
 
 // Tests that an extra adapter changing state does not interfer with the state.
 TEST_F(BluetoothSystemTest, State_ChangeStateMultipleAdapters) {
-  // Start with a powered on "foo" adapter.
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  // Start with a powered on default adapter.
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(
+      kDefaultAdapterObjectPathStr);
 
   auto system = CreateBluetoothSystem();
 
-  // The "foo" adapter is initially powered on.
+  // The default adapter is initially powered on.
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOn, GetStateAndWait(system));
   EXPECT_TRUE(on_state_changed_states_.empty());
 
-  // Add an extra "bar" adapter. The state should not change.
-  test_bluetooth_adapter_client_->SimulateAdapterAdded(kBarObjectPathStr);
+  // Add an extra alternate adapter. The state should not change.
+  test_bluetooth_adapter_client_->SimulateAdapterAdded(
+      kAlternateAdapterObjectPathStr);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOn, GetStateAndWait(system));
   EXPECT_TRUE(on_state_changed_states_.empty());
 
-  // Turn "bar" on. The state should not change.
+  // Turn the alternate adapter on. The state should not change.
   test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(
-      kBarObjectPathStr, true);
+      true, kAlternateAdapterObjectPathStr);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOn, GetStateAndWait(system));
   EXPECT_TRUE(on_state_changed_states_.empty());
 
-  // Turn "bar" off. The state should not change.
+  // Turn the alternate adapter off. The state should not change.
   test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(
-      kBarObjectPathStr, false);
+      false, kAlternateAdapterObjectPathStr);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOn, GetStateAndWait(system));
   EXPECT_TRUE(on_state_changed_states_.empty());
@@ -750,7 +772,7 @@ TEST_F(BluetoothSystemTest, SetPowered_NoAdapter) {
 
 // Tests setting powered to "Off" when the adapter is "Off" already.
 TEST_F(BluetoothSystemTest, SetPoweredOff_SucceedsAdapterInitiallyOff) {
-  test_bluetooth_adapter_client_->SimulateAdapterAdded(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterAdded();
   // Added adapters are Off by default.
 
   auto system = CreateBluetoothSystem();
@@ -759,13 +781,12 @@ TEST_F(BluetoothSystemTest, SetPoweredOff_SucceedsAdapterInitiallyOff) {
   // effect but the call should still succeed.
   EXPECT_EQ(mojom::BluetoothSystem::SetPoweredResult::kSuccess,
             SetPoweredAndWait(system, false));
-  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetSetPoweredCallCount(
-                    kFooObjectPathStr));
+  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetSetPoweredCallCount());
 }
 
 // Tests setting powered to "On" when the adapter is "On" already.
 TEST_F(BluetoothSystemTest, SetPoweredOn_SucceedsAdapterInitiallyOn) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   auto system = CreateBluetoothSystem();
 
@@ -773,26 +794,22 @@ TEST_F(BluetoothSystemTest, SetPoweredOn_SucceedsAdapterInitiallyOn) {
   // effect but the call should still succeed.
   EXPECT_EQ(mojom::BluetoothSystem::SetPoweredResult::kSuccess,
             SetPoweredAndWait(system, true));
-  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetSetPoweredCallCount(
-                    kFooObjectPathStr));
+  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetSetPoweredCallCount());
 }
 
 // Tests successfully setting powered to "Off when the adapter is "On".
 TEST_F(BluetoothSystemTest, SetPoweredOff_SucceedsAdapterInitiallyOn) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   auto system = CreateBluetoothSystem();
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOn, GetStateAndWait(system));
 
   // Try to power off the adapter.
-  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(kFooObjectPathStr,
-                                                            true);
+  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(true);
   EXPECT_EQ(mojom::BluetoothSystem::SetPoweredResult::kSuccess,
             SetPoweredAndWait(system, false));
-  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetSetPoweredCallCount(
-                    kFooObjectPathStr));
-  EXPECT_FALSE(test_bluetooth_adapter_client_->GetLastSetPoweredValue(
-      kFooObjectPathStr));
+  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetSetPoweredCallCount());
+  EXPECT_FALSE(test_bluetooth_adapter_client_->GetLastSetPoweredValue());
   EXPECT_EQ(mojom::BluetoothSystem::State::kTransitioning,
             GetStateAndWait(system));
   EXPECT_EQ(StateVector({mojom::BluetoothSystem::State::kTransitioning}),
@@ -800,8 +817,7 @@ TEST_F(BluetoothSystemTest, SetPoweredOff_SucceedsAdapterInitiallyOn) {
   ResetResults();
 
   // Simulate the adapter actually powering off.
-  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(
-      kFooObjectPathStr, false);
+  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(false);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOff,
             GetStateAndWait(system));
@@ -811,20 +827,17 @@ TEST_F(BluetoothSystemTest, SetPoweredOff_SucceedsAdapterInitiallyOn) {
 
 // Tests successfully setting powered to "On" when the adapter is "Off".
 TEST_F(BluetoothSystemTest, SetPoweredOn_SucceedsAdapterInitiallyOff) {
-  test_bluetooth_adapter_client_->SimulateAdapterAdded(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterAdded();
   // Added adapters are Off by default.
 
   auto system = CreateBluetoothSystem();
 
   // Try to power on the adapter.
-  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(kFooObjectPathStr,
-                                                            true);
+  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(true);
   EXPECT_EQ(mojom::BluetoothSystem::SetPoweredResult::kSuccess,
             SetPoweredAndWait(system, true));
-  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetSetPoweredCallCount(
-                    kFooObjectPathStr));
-  EXPECT_TRUE(test_bluetooth_adapter_client_->GetLastSetPoweredValue(
-      kFooObjectPathStr));
+  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetSetPoweredCallCount());
+  EXPECT_TRUE(test_bluetooth_adapter_client_->GetLastSetPoweredValue());
   EXPECT_EQ(mojom::BluetoothSystem::State::kTransitioning,
             GetStateAndWait(system));
   EXPECT_EQ(StateVector({mojom::BluetoothSystem::State::kTransitioning}),
@@ -832,8 +845,7 @@ TEST_F(BluetoothSystemTest, SetPoweredOn_SucceedsAdapterInitiallyOff) {
   ResetResults();
 
   // Simulate the adapter actually powering on.
-  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(true);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOn, GetStateAndWait(system));
   EXPECT_EQ(StateVector({mojom::BluetoothSystem::State::kPoweredOn}),
@@ -842,19 +854,16 @@ TEST_F(BluetoothSystemTest, SetPoweredOn_SucceedsAdapterInitiallyOff) {
 
 // Tests failing to set powered to "Off when the adapter is "On".
 TEST_F(BluetoothSystemTest, SetPoweredOff_FailsAdapterInitiallyOn) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   auto system = CreateBluetoothSystem();
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOn, GetStateAndWait(system));
 
-  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(kFooObjectPathStr,
-                                                            false);
+  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(false);
   EXPECT_EQ(mojom::BluetoothSystem::SetPoweredResult::kFailedUnknownReason,
             SetPoweredAndWait(system, false));
-  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetSetPoweredCallCount(
-                    kFooObjectPathStr));
-  EXPECT_FALSE(test_bluetooth_adapter_client_->GetLastSetPoweredValue(
-      kFooObjectPathStr));
+  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetSetPoweredCallCount());
+  EXPECT_FALSE(test_bluetooth_adapter_client_->GetLastSetPoweredValue());
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOn, GetStateAndWait(system));
   EXPECT_EQ(StateVector({mojom::BluetoothSystem::State::kTransitioning,
                          mojom::BluetoothSystem::State::kPoweredOn}),
@@ -863,19 +872,16 @@ TEST_F(BluetoothSystemTest, SetPoweredOff_FailsAdapterInitiallyOn) {
 
 // Tests failing to set powered to "On" when the adapter is "Off".
 TEST_F(BluetoothSystemTest, SetPoweredOn_FailsAdapterInitiallyOff) {
-  test_bluetooth_adapter_client_->SimulateAdapterAdded(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterAdded();
   // Added adapters are Off by default.
 
   auto system = CreateBluetoothSystem();
 
-  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(kFooObjectPathStr,
-                                                            false);
+  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(false);
   EXPECT_EQ(mojom::BluetoothSystem::SetPoweredResult::kFailedUnknownReason,
             SetPoweredAndWait(system, true));
-  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetSetPoweredCallCount(
-                    kFooObjectPathStr));
-  EXPECT_TRUE(test_bluetooth_adapter_client_->GetLastSetPoweredValue(
-      kFooObjectPathStr));
+  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetSetPoweredCallCount());
+  EXPECT_TRUE(test_bluetooth_adapter_client_->GetLastSetPoweredValue());
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOff,
             GetStateAndWait(system));
   EXPECT_EQ(StateVector({mojom::BluetoothSystem::State::kTransitioning,
@@ -886,7 +892,7 @@ TEST_F(BluetoothSystemTest, SetPoweredOn_FailsAdapterInitiallyOff) {
 // Tests that the state is correctly updated if the adapter is removed
 // when a call to set powered to "On" is pending.
 TEST_F(BluetoothSystemTest, SetPoweredOn_AdapterRemovedWhilePending) {
-  test_bluetooth_adapter_client_->SimulateAdapterAdded(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterAdded();
   // Added adapters are Off by default.
 
   auto system = CreateBluetoothSystem();
@@ -908,7 +914,7 @@ TEST_F(BluetoothSystemTest, SetPoweredOn_AdapterRemovedWhilePending) {
 
   // Simulate the adapter being removed. This immediately changes the "powered"
   // property of the adapter to `false` and then removes the adapter.
-  test_bluetooth_adapter_client_->SimulateAdapterRemoved(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterRemoved();
   EXPECT_EQ(mojom::BluetoothSystem::State::kUnavailable,
             GetStateAndWait(system));
   EXPECT_EQ(StateVector({mojom::BluetoothSystem::State::kPoweredOff,
@@ -929,7 +935,7 @@ TEST_F(BluetoothSystemTest, SetPoweredOn_AdapterRemovedWhilePending) {
 // Tests that the state is correctly updated if the adapter is removed
 // when a call to set powered to "Off" is pending.
 TEST_F(BluetoothSystemTest, SetPoweredOff_AdapterRemovedWhilePending) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   auto system = CreateBluetoothSystem();
 
@@ -951,7 +957,7 @@ TEST_F(BluetoothSystemTest, SetPoweredOff_AdapterRemovedWhilePending) {
 
   // Simulate the adapter being removed. This immediately changes the "powered"
   // property of the adapter to `false` and then removes the adapter.
-  test_bluetooth_adapter_client_->SimulateAdapterRemoved(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterRemoved();
   EXPECT_EQ(mojom::BluetoothSystem::State::kUnavailable,
             GetStateAndWait(system));
   EXPECT_EQ(StateVector({mojom::BluetoothSystem::State::kPoweredOff,
@@ -980,7 +986,7 @@ TEST_F(BluetoothSystemTest, ScanState_NoAdapter) {
 
 // Tests scan state is kNotScanning when the adapter is not scanning.
 TEST_F(BluetoothSystemTest, ScanState_NotScanning) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
   // Added adapters are not scanning by default.
 
   auto system = CreateBluetoothSystem();
@@ -992,9 +998,8 @@ TEST_F(BluetoothSystemTest, ScanState_NotScanning) {
 
 // Tests scan state is kScanning when the adapter is scanning.
 TEST_F(BluetoothSystemTest, ScanState_Scanning) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
-  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
+  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(true);
 
   auto system = CreateBluetoothSystem();
 
@@ -1006,7 +1011,7 @@ TEST_F(BluetoothSystemTest, ScanState_Scanning) {
 // Tests scan state changes to kScanning when the adapter starts scanning and
 // then changes to kNotScanning when the adapter stops scanning.
 TEST_F(BluetoothSystemTest, ScanState_ScanningThenNotScanning) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   auto system = CreateBluetoothSystem();
 
@@ -1015,8 +1020,7 @@ TEST_F(BluetoothSystemTest, ScanState_ScanningThenNotScanning) {
   EXPECT_TRUE(on_scan_state_changed_states_.empty());
 
   // Adapter starts scanning.
-  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(true);
 
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kScanning,
             GetScanStateAndWait(system));
@@ -1025,8 +1029,7 @@ TEST_F(BluetoothSystemTest, ScanState_ScanningThenNotScanning) {
   ResetResults();
 
   // Adapter stops scanning.
-  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(
-      kFooObjectPathStr, false);
+  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(false);
 
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kNotScanning,
             GetScanStateAndWait(system));
@@ -1037,9 +1040,8 @@ TEST_F(BluetoothSystemTest, ScanState_ScanningThenNotScanning) {
 // Tests scan state is updated as expected when removing and re-adding the same
 // adapter.
 TEST_F(BluetoothSystemTest, ScanState_AdapterRemoved) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
-  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
+  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(true);
 
   auto system = CreateBluetoothSystem();
 
@@ -1048,7 +1050,7 @@ TEST_F(BluetoothSystemTest, ScanState_AdapterRemoved) {
             GetScanStateAndWait(system));
 
   // Remove the adapter. The state should change to not scanning.
-  test_bluetooth_adapter_client_->SimulateAdapterRemoved(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterRemoved();
 
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kNotScanning,
             GetScanStateAndWait(system));
@@ -1057,15 +1059,14 @@ TEST_F(BluetoothSystemTest, ScanState_AdapterRemoved) {
   ResetResults();
 
   // Add the adapter again; it's not scanning by default.
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kNotScanning,
             GetScanStateAndWait(system));
   EXPECT_TRUE(on_scan_state_changed_states_.empty());
 
   // The adapter starts scanning again.
-  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(true);
 
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kScanning,
             GetScanStateAndWait(system));
@@ -1077,9 +1078,10 @@ TEST_F(BluetoothSystemTest, ScanState_AdapterRemoved) {
 // a different adapter.
 TEST_F(BluetoothSystemTest, ScanState_AdapterReplaced) {
   // Start with a scanning adapter.
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(
+      kDefaultAdapterObjectPathStr);
   test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(
-      kFooObjectPathStr, true);
+      true, kDefaultAdapterObjectPathStr);
 
   auto system = CreateBluetoothSystem();
 
@@ -1088,7 +1090,8 @@ TEST_F(BluetoothSystemTest, ScanState_AdapterReplaced) {
             GetScanStateAndWait(system));
 
   // Remove the adapter. The state should change to kNotScanning.
-  test_bluetooth_adapter_client_->SimulateAdapterRemoved(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterRemoved(
+      kDefaultAdapterObjectPathStr);
 
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kNotScanning,
             GetScanStateAndWait(system));
@@ -1097,7 +1100,8 @@ TEST_F(BluetoothSystemTest, ScanState_AdapterReplaced) {
   ResetResults();
 
   // Add a different adapter. It's not scanning by default.
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kBarObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(
+      kAlternateAdapterObjectPathStr);
 
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kNotScanning,
             GetScanStateAndWait(system));
@@ -1105,7 +1109,7 @@ TEST_F(BluetoothSystemTest, ScanState_AdapterReplaced) {
 
   // The new adapter starts scanning.
   test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(
-      kBarObjectPathStr, true);
+      true, kAlternateAdapterObjectPathStr);
 
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kScanning,
             GetScanStateAndWait(system));
@@ -1123,31 +1127,28 @@ TEST_F(BluetoothSystemTest, StartScan_NoAdapter) {
 
 // Tests that StartScan fails if the adapter is "Off".
 TEST_F(BluetoothSystemTest, StartScan_AdapterOff) {
-  test_bluetooth_adapter_client_->SimulateAdapterAdded(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterAdded();
   // Added adapters are Off by default.
 
   auto system = CreateBluetoothSystem();
 
   EXPECT_EQ(mojom::BluetoothSystem::StartScanResult::kBluetoothUnavailable,
             StartScanAndWait(system));
-  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetStartDiscoveryCallCount(
-                    kFooObjectPathStr));
+  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetStartDiscoveryCallCount());
 }
 
 // Tests that StartScan succeeds and the scan state is correctly updated.
 TEST_F(BluetoothSystemTest, StartScan_Succeeds) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   auto system = CreateBluetoothSystem();
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kNotScanning,
             GetScanStateAndWait(system));
 
-  test_bluetooth_adapter_client_->SetNextStartDiscoveryResponse(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SetNextStartDiscoveryResponse(true);
   EXPECT_EQ(mojom::BluetoothSystem::StartScanResult::kSuccess,
             StartScanAndWait(system));
-  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetStartDiscoveryCallCount(
-                    kFooObjectPathStr));
+  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetStartDiscoveryCallCount());
 
   // TODO(ortuno): Test for kTransitioning once implemented.
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kNotScanning,
@@ -1155,8 +1156,7 @@ TEST_F(BluetoothSystemTest, StartScan_Succeeds) {
   EXPECT_EQ(ScanStateVector(), on_scan_state_changed_states_);
   ResetResults();
 
-  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(true);
 
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kScanning,
             GetScanStateAndWait(system));
@@ -1166,19 +1166,17 @@ TEST_F(BluetoothSystemTest, StartScan_Succeeds) {
 
 // Tests that StartScan fails and the scan state is correctly updated.
 TEST_F(BluetoothSystemTest, StartScan_Fails) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   auto system = CreateBluetoothSystem();
 
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kNotScanning,
             GetScanStateAndWait(system));
 
-  test_bluetooth_adapter_client_->SetNextStartDiscoveryResponse(
-      kFooObjectPathStr, false);
+  test_bluetooth_adapter_client_->SetNextStartDiscoveryResponse(false);
   EXPECT_EQ(mojom::BluetoothSystem::StartScanResult::kFailedUnknownReason,
             StartScanAndWait(system));
-  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetStartDiscoveryCallCount(
-                    kFooObjectPathStr));
+  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetStartDiscoveryCallCount());
 
   // TODO(ortuno): Test for kTransitioning once implemented.
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kNotScanning,
@@ -1188,14 +1186,13 @@ TEST_F(BluetoothSystemTest, StartScan_Fails) {
 
 // Tests that StartScan fails when the adapter is powering on.
 TEST_F(BluetoothSystemTest, StartScan_FailsDuringPowerOn) {
-  test_bluetooth_adapter_client_->SimulateAdapterAdded(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterAdded();
   // Added adapters are Off by default.
 
   auto system = CreateBluetoothSystem();
 
   // Start powering on the adapter.
-  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(kFooObjectPathStr,
-                                                            true);
+  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(true);
   EXPECT_EQ(mojom::BluetoothSystem::SetPoweredResult::kSuccess,
             SetPoweredAndWait(system, true));
   EXPECT_EQ(mojom::BluetoothSystem::State::kTransitioning,
@@ -1205,15 +1202,13 @@ TEST_F(BluetoothSystemTest, StartScan_FailsDuringPowerOn) {
   // Start scan should fail without sending the command to the adapter.
   EXPECT_EQ(mojom::BluetoothSystem::StartScanResult::kBluetoothUnavailable,
             StartScanAndWait(system));
-  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetStartDiscoveryCallCount(
-                    kFooObjectPathStr));
+  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetStartDiscoveryCallCount());
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kNotScanning,
             GetScanStateAndWait(system));
   EXPECT_TRUE(on_scan_state_changed_states_.empty());
 
   // Finish powering on the adapter.
-  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(true);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOn, GetStateAndWait(system));
   EXPECT_EQ(StateVector({mojom::BluetoothSystem::State::kPoweredOn}),
@@ -1222,13 +1217,12 @@ TEST_F(BluetoothSystemTest, StartScan_FailsDuringPowerOn) {
 
 // Tests that StartScan fails when the adapter is powering off.
 TEST_F(BluetoothSystemTest, StartScan_FailsDuringPowerOff) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   auto system = CreateBluetoothSystem();
 
   // Start powering off the adapter.
-  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(kFooObjectPathStr,
-                                                            true);
+  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(true);
   EXPECT_EQ(mojom::BluetoothSystem::SetPoweredResult::kSuccess,
             SetPoweredAndWait(system, false));
   EXPECT_EQ(mojom::BluetoothSystem::State::kTransitioning,
@@ -1238,15 +1232,13 @@ TEST_F(BluetoothSystemTest, StartScan_FailsDuringPowerOff) {
   // Start scan should fail without sending the command to the adapter.
   EXPECT_EQ(mojom::BluetoothSystem::StartScanResult::kBluetoothUnavailable,
             StartScanAndWait(system));
-  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetStartDiscoveryCallCount(
-                    kFooObjectPathStr));
+  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetStartDiscoveryCallCount());
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kNotScanning,
             GetScanStateAndWait(system));
   EXPECT_TRUE(on_scan_state_changed_states_.empty());
 
   // Finish powering off the adapter.
-  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(
-      kFooObjectPathStr, false);
+  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(false);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOff,
             GetStateAndWait(system));
@@ -1264,39 +1256,34 @@ TEST_F(BluetoothSystemTest, StopScan_NoAdapter) {
 
 // Tests that StopScan fails if the adapter is "Off".
 TEST_F(BluetoothSystemTest, StopScan_AdapterOff) {
-  test_bluetooth_adapter_client_->SimulateAdapterAdded(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterAdded();
   // Added adapters are Off by default.
 
   auto system = CreateBluetoothSystem();
 
   EXPECT_EQ(mojom::BluetoothSystem::StopScanResult::kBluetoothUnavailable,
             StopScanAndWait(system));
-  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetStopDiscoveryCallCount(
-                    kFooObjectPathStr));
+  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetStopDiscoveryCallCount());
 }
 
 // Tests that StopScan succeeds and the scan state is correctly updated.
 TEST_F(BluetoothSystemTest, StopScan_Succeeds) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   auto system = CreateBluetoothSystem();
 
   // Successfully start scanning.
-  test_bluetooth_adapter_client_->SetNextStartDiscoveryResponse(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SetNextStartDiscoveryResponse(true);
   StartScanAndWait(system);
-  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(true);
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kScanning,
             GetScanStateAndWait(system));
   ResetResults();
 
-  test_bluetooth_adapter_client_->SetNextStopDiscoveryResponse(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SetNextStopDiscoveryResponse(true);
   EXPECT_EQ(mojom::BluetoothSystem::StopScanResult::kSuccess,
             StopScanAndWait(system));
-  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetStopDiscoveryCallCount(
-                    kFooObjectPathStr));
+  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetStopDiscoveryCallCount());
 
   // TODO(ortuno): Test for kTransitioning once implemented.
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kScanning,
@@ -1304,8 +1291,7 @@ TEST_F(BluetoothSystemTest, StopScan_Succeeds) {
   EXPECT_EQ(ScanStateVector(), on_scan_state_changed_states_);
   ResetResults();
 
-  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(
-      kFooObjectPathStr, false);
+  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(false);
 
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kNotScanning,
             GetScanStateAndWait(system));
@@ -1315,26 +1301,22 @@ TEST_F(BluetoothSystemTest, StopScan_Succeeds) {
 
 // Tests that StopScan fails and the scan state is correctly updated.
 TEST_F(BluetoothSystemTest, StopScan_Fails) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   auto system = CreateBluetoothSystem();
 
   // Successfully start scanning.
-  test_bluetooth_adapter_client_->SetNextStartDiscoveryResponse(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SetNextStartDiscoveryResponse(true);
   StartScanAndWait(system);
-  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(true);
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kScanning,
             GetScanStateAndWait(system));
   ResetResults();
 
-  test_bluetooth_adapter_client_->SetNextStopDiscoveryResponse(
-      kFooObjectPathStr, false);
+  test_bluetooth_adapter_client_->SetNextStopDiscoveryResponse(false);
   EXPECT_EQ(mojom::BluetoothSystem::StopScanResult::kFailedUnknownReason,
             StopScanAndWait(system));
-  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetStopDiscoveryCallCount(
-                    kFooObjectPathStr));
+  EXPECT_EQ(1u, test_bluetooth_adapter_client_->GetStopDiscoveryCallCount());
 
   // TODO(ortuno): Test for kTransitioning once implemented.
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kScanning,
@@ -1344,14 +1326,13 @@ TEST_F(BluetoothSystemTest, StopScan_Fails) {
 
 // Tests that StopScan fails if when the adapter is powering on.
 TEST_F(BluetoothSystemTest, StopScan_FailsDuringPowerOn) {
-  test_bluetooth_adapter_client_->SimulateAdapterAdded(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterAdded();
   // Added adapters are Off by default.
 
   auto system = CreateBluetoothSystem();
 
   // Start powering on the adapter.
-  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(kFooObjectPathStr,
-                                                            true);
+  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(true);
   EXPECT_EQ(mojom::BluetoothSystem::SetPoweredResult::kSuccess,
             SetPoweredAndWait(system, true));
   EXPECT_EQ(mojom::BluetoothSystem::State::kTransitioning,
@@ -1361,15 +1342,13 @@ TEST_F(BluetoothSystemTest, StopScan_FailsDuringPowerOn) {
   // Stop scan should fail without sending the command to the adapter.
   EXPECT_EQ(mojom::BluetoothSystem::StopScanResult::kBluetoothUnavailable,
             StopScanAndWait(system));
-  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetStopDiscoveryCallCount(
-                    kFooObjectPathStr));
+  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetStopDiscoveryCallCount());
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kNotScanning,
             GetScanStateAndWait(system));
   EXPECT_TRUE(on_scan_state_changed_states_.empty());
 
   // Finish powering on the adapter.
-  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(true);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOn, GetStateAndWait(system));
   EXPECT_EQ(StateVector({mojom::BluetoothSystem::State::kPoweredOn}),
@@ -1377,23 +1356,20 @@ TEST_F(BluetoothSystemTest, StopScan_FailsDuringPowerOn) {
 }
 
 TEST_F(BluetoothSystemTest, StopScan_FailsDuringPowerOff) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   auto system = CreateBluetoothSystem();
 
   // Start scanning.
-  test_bluetooth_adapter_client_->SetNextStartDiscoveryResponse(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SetNextStartDiscoveryResponse(true);
   EXPECT_EQ(mojom::BluetoothSystem::StartScanResult::kSuccess,
             StartScanAndWait(system));
-  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(true);
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kScanning,
             GetScanStateAndWait(system));
 
   // Start powering off the adapter.
-  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(kFooObjectPathStr,
-                                                            true);
+  test_bluetooth_adapter_client_->SetNextSetPoweredResponse(true);
   EXPECT_EQ(mojom::BluetoothSystem::SetPoweredResult::kSuccess,
             SetPoweredAndWait(system, false));
   EXPECT_EQ(mojom::BluetoothSystem::State::kTransitioning,
@@ -1403,15 +1379,13 @@ TEST_F(BluetoothSystemTest, StopScan_FailsDuringPowerOff) {
   // Stop scan should fail without sending the command to the adapter.
   EXPECT_EQ(mojom::BluetoothSystem::StopScanResult::kBluetoothUnavailable,
             StopScanAndWait(system));
-  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetStopDiscoveryCallCount(
-                    kFooObjectPathStr));
+  EXPECT_EQ(0u, test_bluetooth_adapter_client_->GetStopDiscoveryCallCount());
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kScanning,
             GetScanStateAndWait(system));
   EXPECT_TRUE(on_scan_state_changed_states_.empty());
 
   // Finish powering off the adapter.
-  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(
-      kFooObjectPathStr, false);
+  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(false);
 
   EXPECT_EQ(mojom::BluetoothSystem::State::kPoweredOff,
             GetStateAndWait(system));
@@ -1422,22 +1396,20 @@ TEST_F(BluetoothSystemTest, StopScan_FailsDuringPowerOff) {
 // Tests that the scan state is correctly updated if the adapter is removed
 // during scanning.
 TEST_F(BluetoothSystemTest, Scan_AdapterRemovedWhileScanning) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   auto system = CreateBluetoothSystem();
 
   // Start scanning.
-  test_bluetooth_adapter_client_->SetNextStartDiscoveryResponse(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SetNextStartDiscoveryResponse(true);
   StartScanAndWait(system);
-  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(true);
   ASSERT_EQ(mojom::BluetoothSystem::ScanState::kScanning,
             GetScanStateAndWait(system));
   ResetResults();
 
   // Remove the adapter. Scan state should change to kNotScanning.
-  test_bluetooth_adapter_client_->SimulateAdapterRemoved(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulateAdapterRemoved();
 
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kNotScanning,
             GetScanStateAndWait(system));
@@ -1448,23 +1420,20 @@ TEST_F(BluetoothSystemTest, Scan_AdapterRemovedWhileScanning) {
 // Tests that the scan state is correctly updated if the adapter turns off
 // during scanning.
 TEST_F(BluetoothSystemTest, Scan_PowerOffWhileScanning) {
-  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter(kFooObjectPathStr);
+  test_bluetooth_adapter_client_->SimulatePoweredOnAdapter();
 
   auto system = CreateBluetoothSystem();
 
   // Start scanning.
-  test_bluetooth_adapter_client_->SetNextStartDiscoveryResponse(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SetNextStartDiscoveryResponse(true);
   StartScanAndWait(system);
-  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(
-      kFooObjectPathStr, true);
+  test_bluetooth_adapter_client_->SimulateAdapterDiscoveringStateChanged(true);
   ASSERT_EQ(mojom::BluetoothSystem::ScanState::kScanning,
             GetScanStateAndWait(system));
   ResetResults();
 
   // Power off the adapter. Scan state should change to kNotScanning.
-  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(
-      kFooObjectPathStr, false);
+  test_bluetooth_adapter_client_->SimulateAdapterPowerStateChanged(false);
 
   EXPECT_EQ(mojom::BluetoothSystem::ScanState::kNotScanning,
             GetScanStateAndWait(system));