bluetooth: Implement TrayBluetoothHelperExperimental::GetBluetoothState

Implements GetBluetoothState() by using the new BluetoothSystem mojo
interface.

Bug: 882346
Change-Id: I75f11b9de33c98e2913aeb08a1e5e085532e803d
Reviewed-on: https://chromium-review.googlesource.com/c/1272957
Commit-Queue: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Reviewed-by: Sam McNally <sammc@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599854}

ash/manifest.json

@@ -69,7 +69,10 @@
         "*": [ "accessibility", "app" ],
         "ash_pref_connector": [ "pref_connector" ],
         "catalog": [ "directory" ],
-        "device": [ "device:fingerprint"],
+        "device": [
+          "device:bluetooth_system",
+          "device:fingerprint"
+        ],
         "local_state": [ "pref_client" ],
         "multidevice_setup": [ "multidevice_setup" ],
         "ui": [

ash/shell.cc

@@ -695,7 +695,7 @@ Shell::Shell(std::unique_ptr<ShellDelegate> shell_delegate,
 
   if (base::FeatureList::IsEnabled(features::kUseBluetoothSystemInAsh)) {
     tray_bluetooth_helper_ =
-        std::make_unique<TrayBluetoothHelperExperimental>();
+        std::make_unique<TrayBluetoothHelperExperimental>(connector_);
   } else {
     tray_bluetooth_helper_ = std::make_unique<TrayBluetoothHelperLegacy>();
   }

ash/system/bluetooth/tray_bluetooth_helper_experimental.cc

@@ -5,14 +5,43 @@
 #include "ash/system/bluetooth/tray_bluetooth_helper_experimental.h"
 
 #include <string>
+#include <utility>
+
+#include "ash/shell.h"
+#include "ash/system/tray/system_tray_notifier.h"
+#include "services/device/public/mojom/constants.mojom.h"
+#include "services/service_manager/public/cpp/connector.h"
+#include "services/service_manager/public/cpp/identity.h"
+
+// base::Unretained():
+//
+// Usage of `base::Unretained(this)` is safe when calling BluetoothSystemPtr
+// methods because BluetoothSystemPtr is owned by `this` and guarantees that no
+// callbacks will be run after its destruction.
 
 namespace ash {
 
-TrayBluetoothHelperExperimental::TrayBluetoothHelperExperimental() = default;
+TrayBluetoothHelperExperimental::TrayBluetoothHelperExperimental(
+    service_manager::Connector* connector)
+    : connector_(connector) {}
 
 TrayBluetoothHelperExperimental::~TrayBluetoothHelperExperimental() = default;
 
-void TrayBluetoothHelperExperimental::Initialize() {}
+void TrayBluetoothHelperExperimental::Initialize() {
+  device::mojom::BluetoothSystemFactoryPtr bluetooth_system_factory;
+  connector_->BindInterface(device::mojom::kServiceName,
+                            &bluetooth_system_factory);
+
+  device::mojom::BluetoothSystemClientPtr client_ptr;
+  bluetooth_system_client_binding_.Bind(mojo::MakeRequest(&client_ptr));
+
+  bluetooth_system_factory->Create(mojo::MakeRequest(&bluetooth_system_ptr_),
+                                   std::move(client_ptr));
+  bluetooth_system_ptr_->GetState(
+      base::BindOnce(&TrayBluetoothHelperExperimental::OnStateChanged,
+                     // See base::Unretained() note at the top.
+                     base::Unretained(this)));
+}
 
 BluetoothDeviceList
 TrayBluetoothHelperExperimental::GetAvailableBluetoothDevices() const {
@@ -35,8 +64,7 @@ void TrayBluetoothHelperExperimental::ConnectToBluetoothDevice(
 
 device::mojom::BluetoothSystem::State
 TrayBluetoothHelperExperimental::GetBluetoothState() {
-  NOTIMPLEMENTED();
-  return device::mojom::BluetoothSystem::State::kUnavailable;
+  return cached_state_;
 }
 
 void TrayBluetoothHelperExperimental::SetBluetoothEnabled(bool enabled) {
@@ -48,4 +76,10 @@ bool TrayBluetoothHelperExperimental::HasBluetoothDiscoverySession() {
   return false;
 }
 
+void TrayBluetoothHelperExperimental::OnStateChanged(
+    device::mojom::BluetoothSystem::State state) {
+  cached_state_ = state;
+  Shell::Get()->system_tray_notifier()->NotifyRefreshBluetooth();
+}
+
 }  // namespace ash

ash/system/bluetooth/tray_bluetooth_helper_experimental.h

@@ -10,15 +10,23 @@
 #include "ash/ash_export.h"
 #include "ash/system/bluetooth/tray_bluetooth_helper.h"
 #include "base/macros.h"
+#include "mojo/public/cpp/bindings/binding.h"
 #include "services/device/public/mojom/bluetooth_system.mojom.h"
 
+namespace service_manager {
+class Connector;
+}  // namespace service_manager
+
 namespace ash {
 
 // Implementation of TrayBluetoothHelper on top of the BluetoothSystem Mojo
 // interface.
-class TrayBluetoothHelperExperimental : public TrayBluetoothHelper {
+class TrayBluetoothHelperExperimental
+    : public TrayBluetoothHelper,
+      public device::mojom::BluetoothSystemClient {
  public:
-  TrayBluetoothHelperExperimental();
+  explicit TrayBluetoothHelperExperimental(
+      service_manager::Connector* connector);
   ~TrayBluetoothHelperExperimental() override;
 
   // TrayBluetoothHelper:
@@ -31,7 +39,19 @@ class TrayBluetoothHelperExperimental : public TrayBluetoothHelper {
   void SetBluetoothEnabled(bool enabled) override;
   bool HasBluetoothDiscoverySession() override;
 
+  // device::mojom::BluetoothSystemClient
+  void OnStateChanged(device::mojom::BluetoothSystem::State state) override;
+
  private:
+  service_manager::Connector* connector_;
+
+  device::mojom::BluetoothSystemPtr bluetooth_system_ptr_;
+  mojo::Binding<device::mojom::BluetoothSystemClient>
+      bluetooth_system_client_binding_{this};
+
+  device::mojom::BluetoothSystem::State cached_state_ =
+      device::mojom::BluetoothSystem::State::kUnavailable;
+
   DISALLOW_COPY_AND_ASSIGN(TrayBluetoothHelperExperimental);
 };
 

content/public/app/mojo/content_browser_manifest.json

@@ -105,6 +105,7 @@
         "data_decoder": [ "image_decoder", "json_parser", "xml_parser" ],
         "device": [
           "device:battery_monitor",
+          "device:bluetooth_system",
           "device:generic_sensor",
           "device:geolocation",
           "device:hid",