Revert "bluetooth: Query for devices every second in TrayBluetoothHelper"

This reverts commit e45a6ef0.

Reason for revert: This triggers DCHECKs on device, so reverting. Here's the stack:

[13255:13255:1127/111259.548287:FATAL:tray_bluetooth_helper.cc(50)] Check failed: !timer_.IsRunning().
#0 0x5abde8c02cef base::debug::StackTrace::StackTrace()
#1 0x5abde8b586cb logging::LogMessage::~LogMessage()
#2 0x5abdeb50f0a5 ash::TrayBluetoothHelper::StartOrStopRefreshingDeviceList()
#3 0x5abde9b4ac48 device::BluetoothAdapter::NotifyAdapterPoweredChanged()
#4 0x5abde9b55a5f bluez::BluetoothAdapterBlueZ::SetAdapter()
#5 0x5abde9b7d3d5 bluez::BluetoothAdapterClientImpl::ObjectAdded()
#6 0x5abde9a471be dbus::ObjectManager::AddInterface()
#7 0x5abde9a46d2e dbus::ObjectManager::UpdateObject()
#8 0x5abde9a457fb dbus::ObjectManager::OnGetManagedObjects()
#9 0x5abde505efdc _ZN4base8internal7InvokerINS0_9BindStateIMN8chromeos14BiodClientImplEFvPN4dbus6SignalEEJNS_7WeakPtrIS4_EEEEEFvS7_EE3RunEPNS0_13BindStateBaseES7_
#10 0x5abde9a486bf dbus::ObjectProxy::OnCallMethod()
#11 0x5abde9a4cb43 _ZN4base8internal7InvokerINS0_9BindStateIMN4dbus11ObjectProxyEFvRKNSt3__112basic_stringIcNS5_11char_traitsIcEENS5_9allocatorIcEEEESD_NS_12OnceCallbackIFvPNS3_8ResponseEEEESG_PNS3_13ErrorResponseEEJ13scoped_refptrIS4_ESB_SB_SI_EEEFvSG_SK_EE7RunOnceEPNS0_13BindStateBaseESG_SK_
#12 0x5abde9a49074 dbus::ObjectProxy::RunResponseOrErrorCallback()
#13 0x5abde9a4db5e _ZN4base8internal13FunctorTraitsIMN4dbus11ObjectProxyEFvNS3_19ReplyCallbackHolderENS_9TimeTicksEPNS2_8ResponseEPNS2_13ErrorResponseEEvE6InvokeISB_13scoped_refptrIS3_EJS4_S5_S7_S9_EEEvT_OT0_DpOT1_
#14 0x5abde9a4da80 _ZN4base8internal7InvokerINS0_9BindStateIMN4dbus11ObjectProxyEFvNS4_19ReplyCallbackHolderENS_9TimeTicksEPNS3_8ResponseEPNS3_13ErrorResponseEEJ13scoped_refptrIS4_ES5_S6_S8_SA_EEEFvvEE7RunOnceEPNS0_13BindStateBaseE
#15 0x5abde8bd218b base::(anonymous namespace)::PostTaskAndReplyRelay::RunTaskAndPostReply()
#16 0x5abde8bd260b _ZN4base8internal7InvokerINS0_9BindStateIPFvNS_12_GLOBAL__N_121PostTaskAndReplyRelayEEJS4_EEEFvvEE7RunOnceEPNS0_13BindStateBaseE
#17 0x5abde8c28597 base::debug::TaskAnnotator::RunTask()
#18 0x5abde8b6242f base::MessageLoopImpl::RunTask()
#19 0x5abde8b62ae2 base::MessageLoopImpl::DoWork()
#20 0x5abde8c24189 base::MessagePumpLibevent::Run()
#21 0x5abde8b61f05 base::MessageLoopImpl::Run()
#22 0x5abde8b8c576 base::RunLoop::Run()
#23 0x5abde86a22e5 ChromeBrowserMainParts::MainMessageLoopRun()
#24 0x5abde5eebb04 content::BrowserMainLoop::RunMainMessageLoopParts()
#25 0x5abde5eee503 content::BrowserMainRunnerImpl::Run()
#26 0x5abde5ee828f content::BrowserMain()


Original change's description:
> bluetooth: Query for devices every second in TrayBluetoothHelper
> 
> Before TrayBluetoothHelper would get notified of any changes to devices.
> This caused problems in busy environments because TrayBluetoothHelper
> would get notified hundreds or even thousands of times per second of
> devices changes.
> 
> This CL changes to a "pull" pattern where TrayBluetootHelper queries
> for devices every second. The devices are then cached so that clients
> of TrayBluetoothHelper can access them synchronously.
> 
> TrayBluetoothHelper queries for devices as long as the state is
> kPoweredOn. If the state changes, the device list is cleared.
> 
> Bug: 882346
> 
> TEST=The following actions should be performed:
> 
> 1. Turn bluetooth on and off in system tray.
> 2. Open device list in system menu.
> 3. Connect to a device.
> 4. See that the pod feature button in the system tray indicates a
>    device is connected when connected to a device.
> 
> Change-Id: Id9028546a627f260527aa737f51c032f74a447ec
> Reviewed-on: https://chromium-review.googlesource.com/c/1347638
> Commit-Queue: Giovanni Ortuño Urquidi <ortuno@chromium.org>
> Reviewed-by: Tetsui Ohkubo <tetsui@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#611069}

TBR=ortuno@chromium.org,tetsui@chromium.org

Change-Id: I5b5ca3f227ab7616321047b3a8ade17bfa30b29a
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 882346
Reviewed-on: https://chromium-review.googlesource.com/c/1352340Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611246}

ash/system/bluetooth/bluetooth_feature_pod_controller.cc

@@ -99,7 +99,7 @@ void BluetoothFeaturePodController::UpdateButton() {
        Shell::Get()->tray_bluetooth_helper()->GetAvailableBluetoothDevices()) {
     if (device->connection_state ==
         BluetoothDeviceInfo::ConnectionState::kConnected) {
-      connected_devices.push_back(device->Clone());
+      connected_devices.push_back(std::move(device));
     }
   }
 

ash/system/bluetooth/tray_bluetooth_helper.cc

@@ -3,19 +3,11 @@
 // found in the LICENSE file.
 
 #include "ash/system/bluetooth/tray_bluetooth_helper.h"
-#include "base/time/time.h"
 
 using device::mojom::BluetoothSystem;
 
 namespace ash {
 
-namespace {
-
-constexpr base::TimeDelta kUpdateFrequencyMs =
-    base::TimeDelta::FromMilliseconds(1000);
-
-}  // namespace
-
 TrayBluetoothHelper::TrayBluetoothHelper() = default;
 
 TrayBluetoothHelper::~TrayBluetoothHelper() = default;
@@ -28,11 +20,6 @@ void TrayBluetoothHelper::RemoveObserver(Observer* observer) {
   observers_.RemoveObserver(observer);
 }
 
-const BluetoothDeviceList& TrayBluetoothHelper::GetAvailableBluetoothDevices()
-    const {
-  return cached_devices_;
-}
-
 bool TrayBluetoothHelper::IsBluetoothStateAvailable() {
   switch (GetBluetoothState()) {
     case BluetoothSystem::State::kUnsupported:
@@ -45,36 +32,6 @@ bool TrayBluetoothHelper::IsBluetoothStateAvailable() {
   }
 }
 
-void TrayBluetoothHelper::StartOrStopRefreshingDeviceList() {
-  if (GetBluetoothState() == BluetoothSystem::State::kPoweredOn) {
-    DCHECK(!timer_.IsRunning());
-    UpdateDeviceCache();
-    timer_.Start(FROM_HERE, kUpdateFrequencyMs, this,
-                 &TrayBluetoothHelper::UpdateDeviceCache);
-    return;
-  }
-
-  timer_.Stop();
-  cached_devices_.clear();
-  NotifyBluetoothDeviceListChanged();
-}
-
-void TrayBluetoothHelper::UpdateDeviceCache() {
-  GetBluetoothDevices(
-      base::BindOnce(&TrayBluetoothHelper::OnGetBluetoothDevices,
-                     weak_ptr_factory_.GetWeakPtr()));
-}
-
-void TrayBluetoothHelper::OnGetBluetoothDevices(BluetoothDeviceList devices) {
-  cached_devices_ = std::move(devices);
-  NotifyBluetoothDeviceListChanged();
-}
-
-void TrayBluetoothHelper::NotifyBluetoothDeviceListChanged() {
-  for (auto& observer : observers_)
-    observer.OnBluetoothDeviceListChanged();
-}
-
 void TrayBluetoothHelper::NotifyBluetoothSystemStateChanged() {
   for (auto& observer : observers_)
     observer.OnBluetoothSystemStateChanged();
@@ -85,4 +42,9 @@ void TrayBluetoothHelper::NotifyBluetoothScanStateChanged() {
     observer.OnBluetoothScanStateChanged();
 }
 
+void TrayBluetoothHelper::NotifyBluetoothDeviceListChanged() {
+  for (auto& observer : observers_)
+    observer.OnBluetoothDeviceListChanged();
+}
+
 }  // namespace ash

ash/system/bluetooth/tray_bluetooth_helper.h

@@ -24,7 +24,7 @@ using BluetoothDeviceList = std::vector<device::mojom::BluetoothDeviceInfoPtr>;
 // This is a temporary virtual class used during the migration to the new
 // BluetoothSystem Mojo interface. Once the migration is over, we'll
 // de-virtualize this class and remove its legacy implementation.
-class ASH_EXPORT TrayBluetoothHelper {
+class TrayBluetoothHelper {
  public:
   class Observer : public base::CheckedObserver {
    public:
@@ -48,7 +48,7 @@ class ASH_EXPORT TrayBluetoothHelper {
   virtual void Initialize() = 0;
 
   // Returns a list of available bluetooth devices.
-  const BluetoothDeviceList& GetAvailableBluetoothDevices() const;
+  virtual BluetoothDeviceList GetAvailableBluetoothDevices() const = 0;
 
   // Requests bluetooth start discovering devices, which happens asynchronously.
   virtual void StartBluetoothDiscovering() = 0;
@@ -75,40 +75,13 @@ class ASH_EXPORT TrayBluetoothHelper {
   virtual bool HasBluetoothDiscoverySession() = 0;
 
  protected:
-  using GetBluetoothDevicesCallback =
-      base::OnceCallback<void(BluetoothDeviceList)>;
-
-  // Using a "push" pattern where the underlying API notifies of device changes
-  // is undesireable because there are hundreds or sometimes thousands of
-  // changes per second. This could result in significantly slowing down the UI.
-  // To avoid this we use a pull pattern where we retrieve the device list every
-  // second and notify observers.
-  //
-  // Implementations of TrayBluetoothHelper should call this whenever the state
-  // changes.
-  void StartOrStopRefreshingDeviceList();
-
   void NotifyBluetoothSystemStateChanged();
   void NotifyBluetoothScanStateChanged();
-
-  virtual void GetBluetoothDevices(
-      GetBluetoothDevicesCallback callback) const = 0;
+  void NotifyBluetoothDeviceListChanged();
 
   base::ObserverList<Observer> observers_;
 
  private:
-  void UpdateDeviceCache();
-  void OnGetBluetoothDevices(BluetoothDeviceList devices);
-  void NotifyBluetoothDeviceListChanged();
-
-  // List of cached devices. Updated every second.
-  BluetoothDeviceList cached_devices_;
-
-  // Timer used to update |cached_devices_|.
-  base::RepeatingTimer timer_;
-
-  base::WeakPtrFactory<TrayBluetoothHelper> weak_ptr_factory_{this};
-
   DISALLOW_COPY_AND_ASSIGN(TrayBluetoothHelper);
 };
 

ash/system/bluetooth/tray_bluetooth_helper_experimental.cc

@@ -48,6 +48,12 @@ void TrayBluetoothHelperExperimental::Initialize() {
                      base::Unretained(this)));
 }
 
+BluetoothDeviceList
+TrayBluetoothHelperExperimental::GetAvailableBluetoothDevices() const {
+  NOTIMPLEMENTED();
+  return BluetoothDeviceList();
+}
+
 void TrayBluetoothHelperExperimental::StartBluetoothDiscovering() {
   bluetooth_system_ptr_->StartScan(base::DoNothing());
 }
@@ -75,19 +81,10 @@ bool TrayBluetoothHelperExperimental::HasBluetoothDiscoverySession() {
          device::mojom::BluetoothSystem::ScanState::kScanning;
 }
 
-void TrayBluetoothHelperExperimental::GetBluetoothDevices(
-    GetBluetoothDevicesCallback callback) const {
-  NOTIMPLEMENTED();
-  base::ThreadTaskRunnerHandle::Get()->PostTask(
-      FROM_HERE, base::BindOnce(std::move(callback), BluetoothDeviceList()));
-}
-
 void TrayBluetoothHelperExperimental::OnStateChanged(
     device::mojom::BluetoothSystem::State state) {
   cached_state_ = state;
-
   NotifyBluetoothSystemStateChanged();
-  StartOrStopRefreshingDeviceList();
 }
 
 void TrayBluetoothHelperExperimental::OnScanStateChanged(

ash/system/bluetooth/tray_bluetooth_helper_experimental.h

@@ -31,13 +31,13 @@ class TrayBluetoothHelperExperimental
 
   // TrayBluetoothHelper:
   void Initialize() override;
+  BluetoothDeviceList GetAvailableBluetoothDevices() const override;
   void StartBluetoothDiscovering() override;
   void StopBluetoothDiscovering() override;
   void ConnectToBluetoothDevice(const std::string& address) override;
   device::mojom::BluetoothSystem::State GetBluetoothState() override;
   void SetBluetoothEnabled(bool enabled) override;
   bool HasBluetoothDiscoverySession() override;
-  void GetBluetoothDevices(GetBluetoothDevicesCallback callback) const override;
 
   // device::mojom::BluetoothSystemClient
   void OnStateChanged(device::mojom::BluetoothSystem::State state) override;

ash/system/bluetooth/tray_bluetooth_helper_legacy.cc

@@ -114,8 +114,6 @@ void TrayBluetoothHelperLegacy::InitializeOnAdapterReady(
   adapter_ = adapter;
   CHECK(adapter_);
   adapter_->AddObserver(this);
-
-  StartOrStopRefreshingDeviceList();
 }
 
 void TrayBluetoothHelperLegacy::Initialize() {
@@ -124,6 +122,20 @@ void TrayBluetoothHelperLegacy::Initialize() {
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
+BluetoothDeviceList TrayBluetoothHelperLegacy::GetAvailableBluetoothDevices()
+    const {
+  device::BluetoothAdapter::DeviceList devices =
+      device::FilterBluetoothDeviceList(adapter_->GetDevices(),
+                                        device::BluetoothFilterType::KNOWN,
+                                        kMaximumDevicesShown);
+
+  BluetoothDeviceList device_list;
+  for (device::BluetoothDevice* device : devices)
+    device_list.push_back(GetBluetoothDeviceInfo(device));
+
+  return device_list;
+}
+
 void TrayBluetoothHelperLegacy::StartBluetoothDiscovering() {
   if (HasBluetoothDiscoverySession()) {
     LOG(WARNING) << "Already have active Bluetooth device discovery session.";
@@ -197,20 +209,6 @@ bool TrayBluetoothHelperLegacy::HasBluetoothDiscoverySession() {
   return discovery_session_ && discovery_session_->IsActive();
 }
 
-void TrayBluetoothHelperLegacy::GetBluetoothDevices(
-    GetBluetoothDevicesCallback callback) const {
-  BluetoothDeviceList device_list;
-  device::BluetoothAdapter::DeviceList devices =
-      device::FilterBluetoothDeviceList(adapter_->GetDevices(),
-                                        device::BluetoothFilterType::KNOWN,
-                                        kMaximumDevicesShown);
-  for (device::BluetoothDevice* device : devices)
-    device_list.push_back(GetBluetoothDeviceInfo(device));
-
-  base::ThreadTaskRunnerHandle::Get()->PostTask(
-      FROM_HERE, base::BindOnce(std::move(callback), std::move(device_list)));
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // BluetoothAdapter::Observer:
 
@@ -218,14 +216,12 @@ void TrayBluetoothHelperLegacy::AdapterPresentChanged(
     device::BluetoothAdapter* adapter,
     bool present) {
   NotifyBluetoothSystemStateChanged();
-  StartOrStopRefreshingDeviceList();
 }
 
 void TrayBluetoothHelperLegacy::AdapterPoweredChanged(
     device::BluetoothAdapter* adapter,
     bool powered) {
   NotifyBluetoothSystemStateChanged();
-  StartOrStopRefreshingDeviceList();
 }
 
 void TrayBluetoothHelperLegacy::AdapterDiscoveringChanged(
@@ -234,6 +230,21 @@ void TrayBluetoothHelperLegacy::AdapterDiscoveringChanged(
   NotifyBluetoothScanStateChanged();
 }
 
+void TrayBluetoothHelperLegacy::DeviceAdded(device::BluetoothAdapter* adapter,
+                                            device::BluetoothDevice* device) {
+  NotifyBluetoothDeviceListChanged();
+}
+
+void TrayBluetoothHelperLegacy::DeviceChanged(device::BluetoothAdapter* adapter,
+                                              device::BluetoothDevice* device) {
+  NotifyBluetoothDeviceListChanged();
+}
+
+void TrayBluetoothHelperLegacy::DeviceRemoved(device::BluetoothAdapter* adapter,
+                                              device::BluetoothDevice* device) {
+  NotifyBluetoothDeviceListChanged();
+}
+
 void TrayBluetoothHelperLegacy::OnStartDiscoverySession(
     std::unique_ptr<device::BluetoothDiscoverySession> discovery_session) {
   // If the discovery session was returned after a request to stop discovery

ash/system/bluetooth/tray_bluetooth_helper_legacy.h

@@ -38,13 +38,13 @@ class ASH_EXPORT TrayBluetoothHelperLegacy
 
   // TrayBluetoothHelper:
   void Initialize() override;
+  BluetoothDeviceList GetAvailableBluetoothDevices() const override;
   void StartBluetoothDiscovering() override;
   void StopBluetoothDiscovering() override;
   void ConnectToBluetoothDevice(const std::string& address) override;
   device::mojom::BluetoothSystem::State GetBluetoothState() override;
   void SetBluetoothEnabled(bool enabled) override;
   bool HasBluetoothDiscoverySession() override;
-  void GetBluetoothDevices(GetBluetoothDevicesCallback callback) const override;
 
   // BluetoothAdapter::Observer:
   void AdapterPresentChanged(device::BluetoothAdapter* adapter,
@@ -53,6 +53,12 @@ class ASH_EXPORT TrayBluetoothHelperLegacy
                              bool powered) override;
   void AdapterDiscoveringChanged(device::BluetoothAdapter* adapter,
                                  bool discovering) override;
+  void DeviceAdded(device::BluetoothAdapter* adapter,
+                   device::BluetoothDevice* device) override;
+  void DeviceChanged(device::BluetoothAdapter* adapter,
+                     device::BluetoothDevice* device) override;
+  void DeviceRemoved(device::BluetoothAdapter* adapter,
+                     device::BluetoothDevice* device) override;
 
  private:
   void OnStartDiscoverySession(

ash/system/bluetooth/tray_bluetooth_helper_legacy_unittest.cc

@@ -7,7 +7,6 @@
 #include <string>
 #include <vector>
 
-#include "ash/system/bluetooth/tray_bluetooth_helper.h"
 #include "ash/test/ash_test_base.h"
 #include "base/test/scoped_feature_list.h"
 #include "dbus/object_path.h"
@@ -44,10 +43,6 @@ TEST_F(TrayBluetoothHelperLegacyTest, Basics) {
       static_cast<FakeBluetoothAdapterClient*>(
           BluezDBusManager::Get()->GetBluetoothAdapterClient());
   adapter_client->SetSimulationIntervalMs(0);
-  adapter_client
-      ->GetProperties(
-          dbus::ObjectPath(bluez::FakeBluetoothAdapterClient::kAdapterPath))
-      ->powered.ReplaceValue(true);
 
   FakeBluetoothDeviceClient* device_client =
       static_cast<FakeBluetoothDeviceClient*>(
@@ -64,11 +59,11 @@ TEST_F(TrayBluetoothHelperLegacyTest, Basics) {
   TrayBluetoothHelperLegacy helper;
   helper.Initialize();
   RunAllPendingInMessageLoop();
-  EXPECT_EQ(device::mojom::BluetoothSystem::State::kPoweredOn,
+  EXPECT_EQ(device::mojom::BluetoothSystem::State::kPoweredOff,
             helper.GetBluetoothState());
   EXPECT_FALSE(helper.HasBluetoothDiscoverySession());
 
-  const BluetoothDeviceList& devices = helper.GetAvailableBluetoothDevices();
+  BluetoothDeviceList devices = helper.GetAvailableBluetoothDevices();
   // The devices are fake in tests, so don't assume any particular number.
   EXPECT_FALSE(devices.empty());
   EXPECT_TRUE(ExistInFilteredDevices(
@@ -139,10 +134,6 @@ TEST_F(TrayBluetoothHelperLegacyTest, UnfilteredBluetoothDevices) {
       static_cast<FakeBluetoothAdapterClient*>(
           BluezDBusManager::Get()->GetBluetoothAdapterClient());
   adapter_client->SetSimulationIntervalMs(0);
-  adapter_client
-      ->GetProperties(
-          dbus::ObjectPath(bluez::FakeBluetoothAdapterClient::kAdapterPath))
-      ->powered.ReplaceValue(true);
 
   FakeBluetoothDeviceClient* device_client =
       static_cast<FakeBluetoothDeviceClient*>(
@@ -159,7 +150,7 @@ TEST_F(TrayBluetoothHelperLegacyTest, UnfilteredBluetoothDevices) {
   helper.Initialize();
   base::RunLoop().RunUntilIdle();
 
-  const BluetoothDeviceList& devices = helper.GetAvailableBluetoothDevices();
+  BluetoothDeviceList devices = helper.GetAvailableBluetoothDevices();
   // The devices are fake in tests, so don't assume any particular number.
   EXPECT_TRUE(ExistInFilteredDevices(
       FakeBluetoothDeviceClient::kDisplayPinCodeAddress, devices));

ash/system/bluetooth/unified_bluetooth_detailed_view_controller.cc

@@ -22,6 +22,8 @@ using device::mojom::BluetoothDeviceInfoPtr;
 
 namespace ash {
 
+const int kUpdateFrequencyMs = 1000;
+
 namespace {
 
 // Updates bluetooth device |device| in the |list|. If it is new, append to the
@@ -89,17 +91,27 @@ void UnifiedBluetoothDetailedViewController::OnBluetoothSystemStateChanged() {
   if (bluetooth_state == BluetoothSystem::State::kPoweredOn) {
     // If Bluetooth was just turned on, start discovering.
     Shell::Get()->tray_bluetooth_helper()->StartBluetoothDiscovering();
+  } else {
+    // Otherwise stop updating the list of devices.
+    timer_.Stop();
   }
 
   UpdateDeviceListAndUI();
 }
 
 void UnifiedBluetoothDetailedViewController::OnBluetoothScanStateChanged() {
+  // To avoid delaying showing devices, update the device list and UI
+  // immediately.
   UpdateDeviceListAndUI();
-}
 
-void UnifiedBluetoothDetailedViewController::OnBluetoothDeviceListChanged() {
-  UpdateDeviceListAndUI();
+  if (Shell::Get()->tray_bluetooth_helper()->HasBluetoothDiscoverySession()) {
+    // Update the device list and UI every |kUpdateFrequencyMs|.
+    timer_.Start(
+        FROM_HERE, base::TimeDelta::FromMilliseconds(kUpdateFrequencyMs), this,
+        &UnifiedBluetoothDetailedViewController::UpdateDeviceListAndUI);
+    return;
+  }
+  timer_.Stop();
 }
 
 void UnifiedBluetoothDetailedViewController::UpdateDeviceListAndUI() {
@@ -139,28 +151,25 @@ void UnifiedBluetoothDetailedViewController::UpdateBluetoothDeviceList() {
   std::set<std::string> new_paired_not_connected_devices;
   std::set<std::string> new_discovered_not_paired_devices;
 
-  for (const auto& device :
+  for (auto& device :
        Shell::Get()->tray_bluetooth_helper()->GetAvailableBluetoothDevices()) {
-    auto device_clone = device->Clone();
     if (device->connection_state ==
         BluetoothDeviceInfo::ConnectionState::kConnecting) {
       new_connecting_devices.insert(device->address);
-      UpdateBluetoothDeviceListHelper(&connecting_devices_,
-                                      std::move(device_clone));
+      UpdateBluetoothDeviceListHelper(&connecting_devices_, std::move(device));
     } else if (device->connection_state ==
                    BluetoothDeviceInfo::ConnectionState::kConnected &&
                device->is_paired) {
       new_connected_devices.insert(device->address);
-      UpdateBluetoothDeviceListHelper(&connected_devices_,
-                                      std::move(device_clone));
+      UpdateBluetoothDeviceListHelper(&connected_devices_, std::move(device));
     } else if (device->is_paired) {
       new_paired_not_connected_devices.insert(device->address);
       UpdateBluetoothDeviceListHelper(&paired_not_connected_devices_,
-                                      std::move(device_clone));
+                                      std::move(device));
     } else {
       new_discovered_not_paired_devices.insert(device->address);
       UpdateBluetoothDeviceListHelper(&discovered_not_paired_devices_,
-                                      std::move(device_clone));
+                                      std::move(device));
     }
   }
   RemoveObsoleteBluetoothDevicesFromList(&connecting_devices_,

ash/system/bluetooth/unified_bluetooth_detailed_view_controller.h

@@ -36,7 +36,6 @@ class UnifiedBluetoothDetailedViewController
   // BluetoothObserver:
   void OnBluetoothSystemStateChanged() override;
   void OnBluetoothScanStateChanged() override;
-  void OnBluetoothDeviceListChanged() override;
 
  private:
   void UpdateDeviceListAndUI();
@@ -51,6 +50,9 @@ class UnifiedBluetoothDetailedViewController
   BluetoothDeviceList paired_not_connected_devices_;
   BluetoothDeviceList discovered_not_paired_devices_;
 
+  // Timer used to limit the update frequency.
+  base::RepeatingTimer timer_;
+
   DISALLOW_COPY_AND_ASSIGN(UnifiedBluetoothDetailedViewController);
 };