[Bluetooth] Add battery level field to device::BluetoothDevice.

Also plumb the battery value so that it will be available to Ash Tray
and the Settings UI.

Bug: 785758
Change-Id: I93698c967d92066c388c64a50ad80b81f2aff93f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1642135
Commit-Queue: Alberto Herrera <ahrfgb@google.com>
Reviewed-by: Ryan Hansberry <hansberry@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#669042}

ash/system/bluetooth/tray_bluetooth_helper_legacy.cc

@@ -25,9 +25,11 @@
 #include "device/bluetooth/chromeos/bluetooth_utils.h"
 #include "services/device/public/cpp/bluetooth/bluetooth_utils.h"
 
-using device::mojom::BluetoothSystem;
+using device::mojom::BluetoothDeviceBatteryInfo;
+using device::mojom::BluetoothDeviceBatteryInfoPtr;
 using device::mojom::BluetoothDeviceInfo;
 using device::mojom::BluetoothDeviceInfoPtr;
+using device::mojom::BluetoothSystem;
 
 namespace ash {
 namespace {
@@ -96,6 +98,10 @@ BluetoothDeviceInfoPtr GetBluetoothDeviceInfo(device::BluetoothDevice* device) {
   info->address = AddressStrToBluetoothAddress(device->GetAddress());
   info->name = device->GetName();
   info->is_paired = device->IsPaired();
+  if (device->battery_percentage()) {
+    info->battery_info =
+        BluetoothDeviceBatteryInfo::New(device->battery_percentage().value());
+  }
 
   switch (device->GetDeviceType()) {
     case device::BluetoothDeviceType::UNKNOWN:

device/bluetooth/bluetooth_device.h

@@ -581,6 +581,29 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothDevice {
                           const AbortWriteErrorCallback& error_callback) = 0;
 #endif
 
+  // Set the remaining battery of the device to show in the UI. This value must
+  // be between 0 and 100, inclusive.
+  // TODO(https://crbug.com/973237): Battery percentage is populated by
+  // ash::GattBatteryPoller and used only by Chrome OS. In the future, when
+  // there is a unified Mojo service, this logic will be moved to
+  // BluetoothDeviceInfo.
+  void set_battery_percentage(base::Optional<uint8_t> battery_percentage) {
+    if (battery_percentage) {
+      DCHECK(battery_percentage.value() >= 0 &&
+             battery_percentage.value() <= 100);
+    }
+    battery_percentage_ = battery_percentage;
+  }
+
+  // Returns the remaining battery for the device.
+  // TODO(https://crbug.com/973237): Battery percentage is populated by
+  // ash::GattBatteryPoller and used only by Chrome OS. In the future, when
+  // there is a unified Mojo service, this logic will be moved to
+  // BluetoothDeviceInfo.
+  const base::Optional<uint8_t>& battery_percentage() const {
+    return battery_percentage_;
+  }
+
  protected:
   // BluetoothGattConnection is a friend to call Add/RemoveGattConnection.
   friend BluetoothGattConnection;
@@ -714,6 +737,14 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothDevice {
   // a device type for display when |name_| is empty.
   base::string16 GetAddressWithLocalizedDeviceTypeName() const;
 
+  // Remaining battery level of the device.
+  // TODO(https://crbug.com/973237): This field is populated by
+  // ash::GattBatteryPoller and used only by Chrome OS. This field is different
+  // from others because it is not filled by the platform. In the future, when
+  // there is a unified Mojo service, this field will be moved to
+  // BluetoothDeviceInfo.
+  base::Optional<uint8_t> battery_percentage_;
+
   DISALLOW_COPY_AND_ASSIGN(BluetoothDevice);
 };
 

extensions/browser/api/bluetooth/bluetooth_api_utils.cc

@@ -159,6 +159,11 @@ void BluetoothDeviceToApiDevice(const device::BluetoothDevice& device,
   else
     out->inquiry_tx_power.reset();
 
+  if (device.battery_percentage())
+    out->battery_percentage.reset(new int(device.battery_percentage().value()));
+  else
+    out->battery_percentage.reset();
+
 #if defined(OS_LINUX)
   ConvertTransportToApi(device.GetType(), &(out->transport));
 #endif

extensions/common/api/bluetooth.idl

@@ -96,6 +96,13 @@ namespace bluetooth {
 
     // The transport type of the bluetooth device.
     Transport? transport;
+
+    // The remaining battery of the device.
+    // TODO(https://crbug.com/973237): This field is only used by Chrome OS and
+    // it is different from others because it is not filled by the platform. In
+    // the future, when there is a unified Mojo service, this field will be
+    // moved to BluetoothDeviceInfo.
+    long? batteryPercentage;
   };
 
   dictionary BluetoothFilter {

services/device/public/mojom/bluetooth_system.mojom

@@ -11,6 +11,12 @@ struct BluetoothAddress {
   array<uint8, 6> address;
 };
 
+// These fields are placed in a struct to be nullable.
+struct BluetoothDeviceBatteryInfo {
+  // The remaining battery of the device.
+  uint8 battery_percentage;
+};
+
 // Holds information about a Bluetooth Device.
 struct BluetoothDeviceInfo {
   enum ConnectionState {
@@ -60,6 +66,8 @@ struct BluetoothDeviceInfo {
   // [1] https://www.bluetooth.com/specifications/assigned-numbers/baseband
   // [2] https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.characteristic.gap.appearance.xml
   DeviceType device_type;
+
+  BluetoothDeviceBatteryInfo? battery_info;
 };
 
 // Factory to get an instance of the BluetoothSystem interface.

third_party/closure_compiler/externs/bluetooth.js

@@ -94,7 +94,8 @@ chrome.bluetooth.AdapterState;
  *   uuids: (!Array<string>|undefined),
  *   inquiryRssi: (number|undefined),
  *   inquiryTxPower: (number|undefined),
- *   transport: (!chrome.bluetooth.Transport|undefined)
+ *   transport: (!chrome.bluetooth.Transport|undefined),
+ *   batteryPercentage: (number|undefined)
  * }}
  * @see https://developer.chrome.com/extensions/bluetooth#type-Device
  */