Issue #1391 - Remove the DOM battery API

30 files changed, 0 insertions, 1770 deletions

diff --git a/dom/base/Navigator.cpp b/dom/base/Navigator.cpp
index a544f23c1..53ce2b30f 100644
--- a/dom/base/Navigator.cpp
+++ b/dom/base/Navigator.cpp
@@ -30,7 +30,6 @@
 #include "nsUnicharUtils.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/Telemetry.h"
-#include "BatteryManager.h"
 #ifdef MOZ_GAMEPAD
 #include "mozilla/dom/GamepadServiceTest.h"
 #endif
@@ -197,8 +196,6 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(Navigator)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPermissions)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mGeolocation)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mNotification)
-  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mBatteryManager)
-  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mBatteryPromise)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPowerManager)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mConnection)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mStorageManager)
@@ -249,13 +246,6 @@ Navigator::Invalidate()
     mNotification = nullptr;
   }
 
-  if (mBatteryManager) {
-    mBatteryManager->Shutdown();
-    mBatteryManager = nullptr;
-  }
-
-  mBatteryPromise = nullptr;
-
   if (mPowerManager) {
     mPowerManager->Shutdown();
     mPowerManager = nullptr;
@@ -1321,39 +1311,6 @@ Navigator::GetMozNotification(ErrorResult& aRv)
   return mNotification;
 }
 
-//*****************************************************************************
-//    Navigator::nsINavigatorBattery
-//*****************************************************************************
-
-Promise*
-Navigator::GetBattery(ErrorResult& aRv)
-{
-  if (mBatteryPromise) {
-    return mBatteryPromise;
-  }
-
-  if (!mWindow || !mWindow->GetDocShell()) {
-    aRv.Throw(NS_ERROR_UNEXPECTED);
-    return nullptr;
-  }
-
-  nsCOMPtr<nsIGlobalObject> go = do_QueryInterface(mWindow);
-  RefPtr<Promise> batteryPromise = Promise::Create(go, aRv);
-  if (NS_WARN_IF(aRv.Failed())) {
-    return nullptr;
-  }
-  mBatteryPromise = batteryPromise;
-
-  if (!mBatteryManager) {
-    mBatteryManager = new battery::BatteryManager(mWindow);
-    mBatteryManager->Init();
-  }
-
-  mBatteryPromise->MaybeResolve(mBatteryManager);
-
-  return mBatteryPromise;
-}
-
 PowerManager*
 Navigator::GetMozPower(ErrorResult& aRv)
 {
diff --git a/dom/base/Navigator.h b/dom/base/Navigator.h
index 4ddaaabab..bcc67589e 100644
--- a/dom/base/Navigator.h
+++ b/dom/base/Navigator.h
@@ -51,10 +51,6 @@ namespace dom {
 
 class Permissions;
 
-namespace battery {
-class BatteryManager;
-} // namespace battery
-
 class Promise;
 
 class DesktopNotificationCenter;
@@ -136,7 +132,6 @@ public:
   Permissions* GetPermissions(ErrorResult& aRv);
   // The XPCOM GetDoNotTrack is ok
   Geolocation* GetGeolocation(ErrorResult& aRv);
-  Promise* GetBattery(ErrorResult& aRv);
 
   static void AppName(nsAString& aAppName, bool aUsePrefOverriddenValue);
 
@@ -269,8 +264,6 @@ private:
   RefPtr<Permissions> mPermissions;
   RefPtr<Geolocation> mGeolocation;
   RefPtr<DesktopNotificationCenter> mNotification;
-  RefPtr<battery::BatteryManager> mBatteryManager;
-  RefPtr<Promise> mBatteryPromise;
   RefPtr<PowerManager> mPowerManager;
   RefPtr<network::Connection> mConnection;
 #ifdef MOZ_AUDIO_CHANNEL_MANAGER
diff --git a/dom/base/moz.build b/dom/base/moz.build
index aadafe412..1de49424b 100755
--- a/dom/base/moz.build
+++ b/dom/base/moz.build
@@ -416,7 +416,6 @@ EXTRA_JS_MODULES += [
 ]
 
 LOCAL_INCLUDES += [
-    '../battery',
     '../events',
     '../media',
     '../network',
diff --git a/dom/battery/BatteryManager.cpp b/dom/battery/BatteryManager.cpp
deleted file mode 100644
index 271fa373d..000000000
--- a/dom/battery/BatteryManager.cpp
+++ /dev/null
@@ -1,212 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include <cmath>
-#include <limits>
-#include "BatteryManager.h"
-#include "Constants.h"
-#include "mozilla/DOMEventTargetHelper.h"
-#include "mozilla/Hal.h"
-#include "mozilla/dom/BatteryManagerBinding.h"
-#include "mozilla/Preferences.h"
-#include "nsContentUtils.h"
-#include "nsIDOMClassInfo.h"
-#include "nsIDocument.h"
-
-/**
- * We have to use macros here because our leak analysis tool things we are
- * leaking strings when we have |static const nsString|. Sad :(
- */
-#define LEVELCHANGE_EVENT_NAME           NS_LITERAL_STRING("levelchange")
-#define CHARGINGCHANGE_EVENT_NAME        NS_LITERAL_STRING("chargingchange")
-#define DISCHARGINGTIMECHANGE_EVENT_NAME NS_LITERAL_STRING("dischargingtimechange")
-#define CHARGINGTIMECHANGE_EVENT_NAME    NS_LITERAL_STRING("chargingtimechange")
-
-namespace mozilla {
-namespace dom {
-namespace battery {
-
-BatteryManager::BatteryManager(nsPIDOMWindowInner* aWindow)
-  : DOMEventTargetHelper(aWindow)
-  , mLevel(kDefaultLevel)
-  , mCharging(kDefaultCharging)
-  , mRemainingTime(kDefaultRemainingTime)
-{
-}
-
-void
-BatteryManager::Init()
-{
-  hal::RegisterBatteryObserver(this);
-
-  hal::BatteryInformation batteryInfo;
-  hal::GetCurrentBatteryInformation(&batteryInfo);
-
-  UpdateFromBatteryInfo(batteryInfo);
-}
-
-void
-BatteryManager::Shutdown()
-{
-  hal::UnregisterBatteryObserver(this);
-}
-
-JSObject*
-BatteryManager::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
-{
-  return BatteryManagerBinding::Wrap(aCx, this, aGivenProto);
-}
-
-bool
-BatteryManager::Charging() const
-{
-  MOZ_ASSERT(NS_IsMainThread());
-  // For testing, unable to report the battery status information
-  if (Preferences::GetBool("dom.battery.test.default", false)) {
-    return true;
-  }
-  if (Preferences::GetBool("dom.battery.test.charging", false)) {
-    return true;
-  }
-  if (Preferences::GetBool("dom.battery.test.discharging", false)) {
-    return false;
-  }
-
-  return mCharging;
-}
-
-double
-BatteryManager::DischargingTime() const
-{
-  MOZ_ASSERT(NS_IsMainThread());
-  // For testing, unable to report the battery status information
-  if (Preferences::GetBool("dom.battery.test.default", false)) {
-    return std::numeric_limits<double>::infinity();
-  }
-  if (Preferences::GetBool("dom.battery.test.discharging", false)) {
-    return 42.0;
-  }
-
-  if (Charging() || mRemainingTime == kUnknownRemainingTime) {
-    return std::numeric_limits<double>::infinity();
-  }
-
-  return mRemainingTime;
-}
-
-double
-BatteryManager::ChargingTime() const
-{
-  MOZ_ASSERT(NS_IsMainThread());
-  // For testing, unable to report the battery status information
-  if (Preferences::GetBool("dom.battery.test.default", false)) {
-    return 0.0;
-  }
-  if (Preferences::GetBool("dom.battery.test.charging", false)) {
-    return 42.0;
-  }
-
-  if (!Charging() || mRemainingTime == kUnknownRemainingTime) {
-    return std::numeric_limits<double>::infinity();
-  }
-
-  return mRemainingTime;
-}
-
-double
-BatteryManager::Level() const
-{
-  MOZ_ASSERT(NS_IsMainThread());
-  // For testing, unable to report the battery status information
-  if (Preferences::GetBool("dom.battery.test.default")) {
-    return 1.0;
-  }
-
-  return mLevel;
-}
-
-void
-BatteryManager::UpdateFromBatteryInfo(const hal::BatteryInformation& aBatteryInfo)
-{
-  mLevel = aBatteryInfo.level();
-
-  // Round to the nearest ten percent for non-chrome and non-certified apps
-  nsIDocument* doc = GetOwner() ? GetOwner()->GetDoc() : nullptr;
-  uint16_t status = nsIPrincipal::APP_STATUS_NOT_INSTALLED;
-  if (doc) {
-    status = doc->NodePrincipal()->GetAppStatus();
-  }
-
-  mCharging = aBatteryInfo.charging();
-  mRemainingTime = aBatteryInfo.remainingTime();
-
-  if (!nsContentUtils::IsChromeDoc(doc) &&
-      status != nsIPrincipal::APP_STATUS_CERTIFIED)
-  {
-    mLevel = lround(mLevel * 10.0) / 10.0;
-    if (mLevel == 1.0) {
-      mRemainingTime = mCharging ? kDefaultRemainingTime : kUnknownRemainingTime;
-    } else if (mRemainingTime != kUnknownRemainingTime) {
-      // Round the remaining time to a multiple of 15 minutes and never zero
-      const double MINUTES_15 = 15.0 * 60.0;
-      mRemainingTime = fmax(lround(mRemainingTime / MINUTES_15) * MINUTES_15,
-                            MINUTES_15);
-    }
-  }
-
-  // Add some guards to make sure the values are coherent.
-  if (mLevel == 1.0 && mCharging == true &&
-      mRemainingTime != kDefaultRemainingTime) {
-    mRemainingTime = kDefaultRemainingTime;
-    NS_ERROR("Battery API: When charging and level at 1.0, remaining time "
-             "should be 0. Please fix your backend!");
-  }
-}
-
-void
-BatteryManager::Notify(const hal::BatteryInformation& aBatteryInfo)
-{
-  double previousLevel = mLevel;
-  bool previousCharging = mCharging;
-  double previousRemainingTime = mRemainingTime;
-
-  UpdateFromBatteryInfo(aBatteryInfo);
-
-  if (previousCharging != mCharging) {
-    DispatchTrustedEvent(CHARGINGCHANGE_EVENT_NAME);
-  }
-
-  if (previousLevel != mLevel) {
-    DispatchTrustedEvent(LEVELCHANGE_EVENT_NAME);
-  }
-
-  /*
-   * There are a few situations that could happen here:
-   * 1. Charging state changed:
-   *   a. Previous remaining time wasn't unkwonw, we have to fire an event for
-   *      the change.
-   *   b. New remaining time isn't unkwonw, we have to fire an event for it.
-   * 2. Charging state didn't change but remainingTime did, we have to fire
-   *    the event that correspond to the current charging state.
-   */
-  if (mCharging != previousCharging) {
-    if (previousRemainingTime != kUnknownRemainingTime) {
-      DispatchTrustedEvent(previousCharging ? CHARGINGTIMECHANGE_EVENT_NAME
-                                            : DISCHARGINGTIMECHANGE_EVENT_NAME);
-    }
-    if (mRemainingTime != kUnknownRemainingTime) {
-      DispatchTrustedEvent(mCharging ? CHARGINGTIMECHANGE_EVENT_NAME
-                                     : DISCHARGINGTIMECHANGE_EVENT_NAME);
-    }
-  } else if (previousRemainingTime != mRemainingTime) {
-    DispatchTrustedEvent(mCharging ? CHARGINGTIMECHANGE_EVENT_NAME
-                                   : DISCHARGINGTIMECHANGE_EVENT_NAME);
-  }
-}
-
-} // namespace battery
-} // namespace dom
-} // namespace mozilla
diff --git a/dom/battery/BatteryManager.h b/dom/battery/BatteryManager.h
deleted file mode 100644
index 4094c40d4..000000000
--- a/dom/battery/BatteryManager.h
+++ /dev/null
@@ -1,84 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#ifndef mozilla_dom_battery_BatteryManager_h
-#define mozilla_dom_battery_BatteryManager_h
-
-#include "Types.h"
-#include "mozilla/DOMEventTargetHelper.h"
-#include "mozilla/Observer.h"
-#include "nsCycleCollectionParticipant.h"
-
-namespace mozilla {
-
-namespace hal {
-class BatteryInformation;
-} // namespace hal
-
-namespace dom {
-namespace battery {
-
-class BatteryManager : public DOMEventTargetHelper
-                     , public BatteryObserver
-{
-public:
-  explicit BatteryManager(nsPIDOMWindowInner* aWindow);
-
-  void Init();
-  void Shutdown();
-
-  // For IObserver.
-  void Notify(const hal::BatteryInformation& aBatteryInfo) override;
-
-  /**
-   * WebIDL Interface
-   */
-
-  nsPIDOMWindowInner* GetParentObject() const
-  {
-     return GetOwner();
-  }
-
-  virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
-
-  bool Charging() const;
-
-  double ChargingTime() const;
-
-  double DischargingTime() const;
-
-  double Level() const;
-
-  IMPL_EVENT_HANDLER(chargingchange)
-  IMPL_EVENT_HANDLER(chargingtimechange)
-  IMPL_EVENT_HANDLER(dischargingtimechange)
-  IMPL_EVENT_HANDLER(levelchange)
-
-private:
-  /**
-   * Update the battery information stored in the battery manager object using
-   * a battery information object.
-   */
-  void UpdateFromBatteryInfo(const hal::BatteryInformation& aBatteryInfo);
-
-  /**
-   * Represents the battery level, ranging from 0.0 (dead or removed?)
-   * to 1.0 (fully charged)
-   */
-  double mLevel;
-  bool   mCharging;
-  /**
-   * Represents the discharging time or the charging time, depending on the
-   * current battery status (charging or not).
-   */
-  double mRemainingTime;
-};
-
-} // namespace battery
-} // namespace dom
-} // namespace mozilla
-
-#endif // mozilla_dom_battery_BatteryManager_h
diff --git a/dom/battery/Constants.h b/dom/battery/Constants.h
deleted file mode 100644
index f642e2a46..000000000
--- a/dom/battery/Constants.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#ifndef mozilla_dom_battery_Constants_h__
-#define mozilla_dom_battery_Constants_h__
-
-/**
- * A set of constants that might need to be used by battery backends.
- * It's not part of BatteryManager.h to prevent those backends to include it.
- */
-namespace mozilla {
-namespace dom {
-namespace battery {
-
-  static const double kDefaultLevel         = 1.0;
-  static const bool   kDefaultCharging      = true;
-  static const double kDefaultRemainingTime = 0;
-  static const double kUnknownRemainingTime = -1;
-
-} // namespace battery
-} // namespace dom
-} // namespace mozilla
-
-#endif // mozilla_dom_battery_Constants_h__
diff --git a/dom/battery/Types.h b/dom/battery/Types.h
deleted file mode 100644
index ee55a26d3..000000000
--- a/dom/battery/Types.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#ifndef mozilla_dom_battery_Types_h
-#define mozilla_dom_battery_Types_h
-
-namespace mozilla {
-namespace hal {
-class BatteryInformation;
-} // namespace hal
-
-template <class T>
-class Observer;
-
-typedef Observer<hal::BatteryInformation> BatteryObserver;
-
-} // namespace mozilla
-
-#endif // mozilla_dom_battery_Types_h
-
diff --git a/dom/battery/moz.build b/dom/battery/moz.build
deleted file mode 100644
index e3743c40b..000000000
--- a/dom/battery/moz.build
+++ /dev/null
@@ -1,21 +0,0 @@
-# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
-# vim: set filetype=python:
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-EXPORTS.mozilla.dom.battery += [
-    'Constants.h',
-    'Types.h',
-]
-
-SOURCES += [
-    'BatteryManager.cpp',
-]
-
-include('/ipc/chromium/chromium-config.mozbuild')
-
-FINAL_LIBRARY = 'xul'
-
-MOCHITEST_CHROME_MANIFESTS += ['test/chrome.ini']
-MOCHITEST_MANIFESTS += ['test/mochitest.ini']
diff --git a/dom/battery/test/chrome.ini b/dom/battery/test/chrome.ini
deleted file mode 100644
index ced199bff..000000000
--- a/dom/battery/test/chrome.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[test_battery_basics.html]
-[test_battery_charging.html]
-[test_battery_discharging.html]
diff --git a/dom/battery/test/mochitest.ini b/dom/battery/test/mochitest.ini
deleted file mode 100644
index 4d8307930..000000000
--- a/dom/battery/test/mochitest.ini
+++ /dev/null
@@ -1 +0,0 @@
-[test_battery_unprivileged.html]
diff --git a/dom/battery/test/test_battery_basics.html b/dom/battery/test/test_battery_basics.html
deleted file mode 100644
index 96f7f3368..000000000
--- a/dom/battery/test/test_battery_basics.html
+++ /dev/null
@@ -1,39 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<head>
-  <title>Test for Battery API</title>
-  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
-  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
-</head>
-<body>
-<p id="display"></p>
-<div id="content" style="display: none">
-</div>
-<pre id="test">
-<script type="application/javascript">
-
-"use strict";
-
-SimpleTest.waitForExplicitFinish();
-
-/** Test for Battery API **/
-ok("getBattery" in navigator, "navigator.getBattery should exist");
-ok(!("battery" in navigator), "navigator.battery should not exist");
-
-navigator.getBattery().then(function (battery) {
-  ok(battery.level >= 0.0 && battery.level <= 1.0, "Battery level " + battery.level + " should be in the range [0.0, 1.0]");
-
-  SpecialPowers.pushPrefEnv({"set": [["dom.battery.test.default", true]]}, function () {
-    ok(battery.charging, "Battery should be charging by default");
-    is(battery.chargingTime, 0, "Battery chargingTime " + battery.chargingTime + " should be zero by default");
-    is(battery.dischargingTime, Infinity, "Battery dischargingTime should be Infinity by default");
-    is(battery.level, 1.0, "Battery level " + battery.level + " should be 1.0 by default");
-
-    SimpleTest.finish();
-  });
-});
-
-</script>
-</pre>
-</body>
-</html>
diff --git a/dom/battery/test/test_battery_charging.html b/dom/battery/test/test_battery_charging.html
deleted file mode 100644
index 5d1e83284..000000000
--- a/dom/battery/test/test_battery_charging.html
+++ /dev/null
@@ -1,35 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<head>
-  <title>Test for Battery API</title>
-  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
-  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
-</head>
-<body>
-<p id="display"></p>
-<div id="content" style="display: none">
-</div>
-<pre id="test">
-<script type="application/javascript">
-
-"use strict";
-
-SimpleTest.waitForExplicitFinish();
-
-/** Test for Battery API **/
-navigator.getBattery().then(function (battery) {
-  ok(battery.level >= 0.0 && battery.level <= 1.0, "Battery level " + battery.level + " should be in the range [0.0, 1.0]");
-
-  SpecialPowers.pushPrefEnv({"set": [["dom.battery.test.charging", true]]}, function () {
-    is(battery.charging, true, "Battery should be charging");
-    ok(battery.chargingTime >= 0, "Battery chargingTime " + battery.chargingTime + " should be nonnegative when charging");
-    is(battery.dischargingTime, Infinity, "Battery dischargingTime should be Infinity when charging");
-
-    SimpleTest.finish();
-  });
-});
-
-</script>
-</pre>
-</body>
-</html>
diff --git a/dom/battery/test/test_battery_discharging.html b/dom/battery/test/test_battery_discharging.html
deleted file mode 100644
index 26a0359d3..000000000
--- a/dom/battery/test/test_battery_discharging.html
+++ /dev/null
@@ -1,35 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<head>
-  <title>Test for Battery API</title>
-  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
-  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
-</head>
-<body>
-<p id="display"></p>
-<div id="content" style="display: none">
-</div>
-<pre id="test">
-<script type="application/javascript">
-
-"use strict";
-
-SimpleTest.waitForExplicitFinish();
-
-/** Test for Battery API **/
-navigator.getBattery().then(function (battery) {
-  ok(battery.level >= 0.0 && battery.level <= 1.0, "Battery level " + battery.level + " should be in the range [0.0, 1.0]");
-
-  SpecialPowers.pushPrefEnv({"set": [["dom.battery.test.discharging", true]]}, function () {
-    is(battery.charging, false, "Battery should be discharging");
-    is(battery.chargingTime, Infinity, "Battery chargingTime should be Infinity when discharging");
-    ok(battery.dischargingTime > 0, "Battery dischargingTime " + battery.dischargingTime + " should be positive when discharging");
-
-    SimpleTest.finish();
-  });
-});
-
-</script>
-</pre>
-</body>
-</html>
diff --git a/dom/battery/test/test_battery_unprivileged.html b/dom/battery/test/test_battery_unprivileged.html
deleted file mode 100644
index e56db8ac7..000000000
--- a/dom/battery/test/test_battery_unprivileged.html
+++ /dev/null
@@ -1,24 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<head>
-  <title>Test for Battery API</title>
-  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
-  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
-</head>
-<body>
-<p id="display"></p>
-<div id="content" style="display: none">
-</div>
-<pre id="test">
-<script type="application/javascript">
-
-"use strict";
-
-/** Test for Battery API **/
-ok(!("getBattery" in navigator), "navigator.getBattery should not exist for unprivileged web content");
-ok(!("battery" in navigator), "navigator.battery should not exist");
-
-</script>
-</pre>
-</body>
-</html>
diff --git a/dom/bindings/moz.build b/dom/bindings/moz.build
index 649689c41..8fc62ba99 100644
--- a/dom/bindings/moz.build
+++ b/dom/bindings/moz.build
@@ -64,7 +64,6 @@ LOCAL_INCLUDES += [
 
 LOCAL_INCLUDES += [
     '/dom/base',
-    '/dom/battery',
     '/dom/canvas',
     '/dom/geolocation',
     '/dom/html',
diff --git a/dom/moz.build b/dom/moz.build
index 7888ccd69..e232f3443 100644
--- a/dom/moz.build
+++ b/dom/moz.build
@@ -43,7 +43,6 @@ DIRS += [
     'base',
     'archivereader',
     'bindings',
-    'battery',
     'browser-element',
     'cache',
     'canvas',
diff --git a/dom/quota/QuotaManagerService.cpp b/dom/quota/QuotaManagerService.cpp
index bd811dc9b..22b5d17b1 100644
--- a/dom/quota/QuotaManagerService.cpp
+++ b/dom/quota/QuotaManagerService.cpp
@@ -432,30 +432,6 @@ QuotaManagerService::PerformIdleMaintenance()
   MOZ_ASSERT(XRE_IsParentProcess());
   MOZ_ASSERT(NS_IsMainThread());
 
-  // If we're running on battery power then skip all idle maintenance since we
-  // would otherwise be doing lots of disk I/O.
-  BatteryInformation batteryInfo;
-
-#ifdef MOZ_WIDGET_ANDROID
-  // Android XPCShell doesn't load the AndroidBridge that is needed to make
-  // GetCurrentBatteryInformation work...
-  if (!QuotaManager::IsRunningXPCShellTests())
-#endif
-  {
-    GetCurrentBatteryInformation(&batteryInfo);
-  }
-
-  // If we're running XPCShell because we always want to be able to test this
-  // code so pretend that we're always charging.
-  if (QuotaManager::IsRunningXPCShellTests()) {
-    batteryInfo.level() = 100;
-    batteryInfo.charging() = true;
-  }
-
-  if (NS_WARN_IF(!batteryInfo.charging())) {
-    return;
-  }
-
   if (QuotaManager::IsRunningXPCShellTests()) {
     // We don't want user activity to impact this code if we're running tests.
     Unused << Observe(nullptr, OBSERVER_TOPIC_IDLE, nullptr);
diff --git a/dom/webidl/BatteryManager.webidl b/dom/webidl/BatteryManager.webidl
deleted file mode 100644
index a964f3b0b..000000000
--- a/dom/webidl/BatteryManager.webidl
+++ /dev/null
@@ -1,23 +0,0 @@
-/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/.
- *
- * The origin of this IDL file is
- * http://www.w3.org/TR/battery-status/
- *
- * Copyright © 2012 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C
- * liability, trademark and document use rules apply.
- */
-
-interface BatteryManager : EventTarget {
-    readonly attribute boolean             charging;
-    readonly attribute unrestricted double chargingTime;
-    readonly attribute unrestricted double dischargingTime;
-    readonly attribute double              level;
-
-             attribute EventHandler        onchargingchange;
-             attribute EventHandler        onchargingtimechange;
-             attribute EventHandler        ondischargingtimechange;
-             attribute EventHandler        onlevelchange;
-};
diff --git a/dom/webidl/Navigator.webidl b/dom/webidl/Navigator.webidl
index 4536d7d25..f34429de7 100644
--- a/dom/webidl/Navigator.webidl
+++ b/dom/webidl/Navigator.webidl
@@ -7,7 +7,6 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#the-navigator-object
  * http://www.w3.org/TR/tracking-dnt/
  * http://www.w3.org/TR/geolocation-API/#geolocation_interface
- * http://www.w3.org/TR/battery-status/#navigatorbattery-interface
  * http://www.w3.org/TR/vibration/#vibration-interface
  * http://www.w3.org/2012/sysapps/runtime/#extension-to-the-navigator-interface-1
  * https://dvcs.w3.org/hg/gamepad/raw-file/default/gamepad.html#navigator-interface-extension
@@ -125,13 +124,6 @@ interface NavigatorGeolocation {
 };
 Navigator implements NavigatorGeolocation;
 
-// http://www.w3.org/TR/battery-status/#navigatorbattery-interface
-partial interface Navigator {
-  // ChromeOnly to prevent web content from fingerprinting users' batteries.
-  [Throws, ChromeOnly, Pref="dom.battery.enabled"]
-  Promise<BatteryManager> getBattery();
-};
-
 // http://www.w3.org/TR/vibration/#vibration-interface
 partial interface Navigator {
     // We don't support sequences in unions yet
diff --git a/dom/webidl/moz.build b/dom/webidl/moz.build
index d8309c265..687e502fa 100644
--- a/dom/webidl/moz.build
+++ b/dom/webidl/moz.build
@@ -50,7 +50,6 @@ WEBIDL_FILES = [
     'AutocompleteInfo.webidl',
     'BarProp.webidl',
     'BaseKeyframeTypes.webidl',
-    'BatteryManager.webidl',
     'BeforeAfterKeyboardEvent.webidl',
     'BeforeUnloadEvent.webidl',
     'BiquadFilterNode.webidl',
diff --git a/hal/Hal.cpp b/hal/Hal.cpp
index 67930c355..981f49125 100644
--- a/hal/Hal.cpp
+++ b/hal/Hal.cpp
@@ -264,30 +264,6 @@ private:
   bool                    mHasValidCache;
 };
 
-class BatteryObserversManager : public CachingObserversManager<BatteryInformation>
-{
-protected:
-  void EnableNotifications() {
-    PROXY_IF_SANDBOXED(EnableBatteryNotifications());
-  }
-
-  void DisableNotifications() {
-    PROXY_IF_SANDBOXED(DisableBatteryNotifications());
-  }
-
-  void GetCurrentInformationInternal(BatteryInformation* aInfo) {
-    PROXY_IF_SANDBOXED(GetCurrentBatteryInformation(aInfo));
-  }
-};
-
-static BatteryObserversManager&
-BatteryObservers()
-{
-  static BatteryObserversManager sBatteryObservers;
-  AssertMainThread();
-  return sBatteryObservers;
-}
-
 class NetworkObserversManager : public CachingObserversManager<NetworkInformation>
 {
 protected:
@@ -356,35 +332,6 @@ ScreenConfigurationObservers()
   return sScreenConfigurationObservers;
 }
 
-void
-RegisterBatteryObserver(BatteryObserver* aObserver)
-{
-  AssertMainThread();
-  BatteryObservers().AddObserver(aObserver);
-}
-
-void
-UnregisterBatteryObserver(BatteryObserver* aObserver)
-{
-  AssertMainThread();
-  BatteryObservers().RemoveObserver(aObserver);
-}
-
-void
-GetCurrentBatteryInformation(BatteryInformation* aInfo)
-{
-  AssertMainThread();
-  *aInfo = BatteryObservers().GetCurrentInformation();
-}
-
-void
-NotifyBatteryChange(const BatteryInformation& aInfo)
-{
-  AssertMainThread();
-  BatteryObservers().CacheInformation(aInfo);
-  BatteryObservers().BroadcastCachedInformation();
-}
-
 bool GetScreenEnabled()
 {
   AssertMainThread();
diff --git a/hal/Hal.h b/hal/Hal.h
index 5411b387a..53c9e68bb 100644
--- a/hal/Hal.h
+++ b/hal/Hal.h
@@ -10,7 +10,6 @@
 #include "base/basictypes.h"
 #include "base/platform_thread.h"
 #include "nsTArray.h"
-#include "mozilla/dom/battery/Types.h"
 #include "mozilla/dom/MozPowerManagerBinding.h"
 #include "mozilla/dom/network/Types.h"
 #include "mozilla/dom/power/Types.h"
@@ -88,29 +87,6 @@ void CancelVibrate(nsPIDOMWindowInner* aWindow);
 void CancelVibrate(const hal::WindowIdentifier &id);
 
 /**
- * Inform the battery backend there is a new battery observer.
- * @param aBatteryObserver The observer that should be added.
- */
-void RegisterBatteryObserver(BatteryObserver* aBatteryObserver);
-
-/**
- * Inform the battery backend a battery observer unregistered.
- * @param aBatteryObserver The observer that should be removed.
- */
-void UnregisterBatteryObserver(BatteryObserver* aBatteryObserver);
-
-/**
- * Returns the current battery information.
- */
-void GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo);
-
-/**
- * Notify of a change in the battery state.
- * @param aBatteryInfo The new battery information.
- */
-void NotifyBatteryChange(const hal::BatteryInformation& aBatteryInfo);
-
-/**
  * Determine whether the device's screen is currently enabled.
  */
 bool GetScreenEnabled();
diff --git a/hal/cocoa/CocoaBattery.cpp b/hal/cocoa/CocoaBattery.cpp
deleted file mode 100644
index 6f1b7b1dc..000000000
--- a/hal/cocoa/CocoaBattery.cpp
+++ /dev/null
@@ -1,325 +0,0 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim set: sw=2 ts=2 et lcs=trail\:.,tab\:>~ : */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#import <CoreFoundation/CoreFoundation.h>
-#import <IOKit/ps/IOPowerSources.h>
-#import <IOKit/ps/IOPSKeys.h>
-
-#include <mozilla/Hal.h>
-#include <mozilla/dom/battery/Constants.h>
-#include <mozilla/Services.h>
-
-#include <nsIObserverService.h>
-#include <nsIObserver.h>
-
-#include <dlfcn.h>
-
-#define IOKIT_FRAMEWORK_PATH "/System/Library/Frameworks/IOKit.framework/IOKit"
-
-#ifndef kIOPSTimeRemainingUnknown
-  #define kIOPSTimeRemainingUnknown ((CFTimeInterval)-1.0)
-#endif
-#ifndef kIOPSTimeRemainingUnlimited
-  #define kIOPSTimeRemainingUnlimited ((CFTimeInterval)-2.0)
-#endif
-
-using namespace mozilla::dom::battery;
-
-namespace mozilla {
-namespace hal_impl {
-
-typedef CFTimeInterval (*IOPSGetTimeRemainingEstimateFunc)(void);
-
-class MacPowerInformationService
-{
-public:
-  static MacPowerInformationService* GetInstance();
-  static void Shutdown();
-  static bool IsShuttingDown();
-
-  void BeginListening();
-  void StopListening();
-
-  static void HandleChange(void *aContext);
-
-  ~MacPowerInformationService();
-
-private:
-  MacPowerInformationService();
-
-  // The reference to the runloop that is notified of power changes.
-  CFRunLoopSourceRef mRunLoopSource;
-
-  double mLevel;
-  bool mCharging;
-  double mRemainingTime;
-  bool mShouldNotify;
-
-  friend void GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo);
-
-  static MacPowerInformationService* sInstance;
-  static bool sShuttingDown;
-
-  static void* sIOKitFramework;
-  static IOPSGetTimeRemainingEstimateFunc sIOPSGetTimeRemainingEstimate;
-};
-
-void* MacPowerInformationService::sIOKitFramework;
-IOPSGetTimeRemainingEstimateFunc MacPowerInformationService::sIOPSGetTimeRemainingEstimate;
-
-/*
- * Implementation of mozilla::hal_impl::EnableBatteryNotifications,
- *                   mozilla::hal_impl::DisableBatteryNotifications,
- *               and mozilla::hal_impl::GetCurrentBatteryInformation.
- */
-
-void
-EnableBatteryNotifications()
-{
-  if (!MacPowerInformationService::IsShuttingDown()) {
-    MacPowerInformationService::GetInstance()->BeginListening();
-  }
-}
-
-void
-DisableBatteryNotifications()
-{
-  if (!MacPowerInformationService::IsShuttingDown()) {
-    MacPowerInformationService::GetInstance()->StopListening();
-  }
-}
-
-void
-GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo)
-{
-  MacPowerInformationService* powerService = MacPowerInformationService::GetInstance();
-
-  aBatteryInfo->level() = powerService->mLevel;
-  aBatteryInfo->charging() = powerService->mCharging;
-  aBatteryInfo->remainingTime() = powerService->mRemainingTime;
-}
-
-bool MacPowerInformationService::sShuttingDown = false;
-
-/*
- * Following is the implementation of MacPowerInformationService.
- */
-
-MacPowerInformationService* MacPowerInformationService::sInstance = nullptr;
-
-namespace {
-struct SingletonDestroyer final : public nsIObserver
-{
-  NS_DECL_ISUPPORTS
-  NS_DECL_NSIOBSERVER
-
-private:
-  ~SingletonDestroyer() {}
-};
-
-NS_IMPL_ISUPPORTS(SingletonDestroyer, nsIObserver)
-
-NS_IMETHODIMP
-SingletonDestroyer::Observe(nsISupports*, const char* aTopic, const char16_t*)
-{
-  MOZ_ASSERT(!strcmp(aTopic, "xpcom-shutdown"));
-  MacPowerInformationService::Shutdown();
-  return NS_OK;
-}
-} // namespace
-
-/* static */ MacPowerInformationService*
-MacPowerInformationService::GetInstance()
-{
-  if (sInstance) {
-    return sInstance;
-  }
-
-  sInstance = new MacPowerInformationService();
-
-  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
-  if (obs) {
-    obs->AddObserver(new SingletonDestroyer(), "xpcom-shutdown", false);
-  }
-
-  return sInstance;
-}
-
-bool
-MacPowerInformationService::IsShuttingDown()
-{
-  return sShuttingDown;
-}
-
-void
-MacPowerInformationService::Shutdown()
-{
-  sShuttingDown = true;
-  delete sInstance;
-  sInstance = nullptr;
-}
-
-MacPowerInformationService::MacPowerInformationService()
-  : mRunLoopSource(nullptr)
-  , mLevel(kDefaultLevel)
-  , mCharging(kDefaultCharging)
-  , mRemainingTime(kDefaultRemainingTime)
-  , mShouldNotify(false)
-{
-  // IOPSGetTimeRemainingEstimate (and the related constants) are only available
-  // on 10.7, so we test for their presence at runtime.
-  sIOKitFramework = dlopen(IOKIT_FRAMEWORK_PATH, RTLD_LAZY | RTLD_LOCAL);
-  if (sIOKitFramework) {
-    sIOPSGetTimeRemainingEstimate =
-      (IOPSGetTimeRemainingEstimateFunc)dlsym(sIOKitFramework, "IOPSGetTimeRemainingEstimate");
-  } else {
-    sIOPSGetTimeRemainingEstimate = nullptr;
-  }
-}
-
-MacPowerInformationService::~MacPowerInformationService()
-{
-  MOZ_ASSERT(!mRunLoopSource,
-               "The observers have not been correctly removed! "
-               "(StopListening should have been called)");
-
-  if (sIOKitFramework) {
-    dlclose(sIOKitFramework);
-  }
-}
-
-void
-MacPowerInformationService::BeginListening()
-{
-  // Set ourselves up to be notified about changes.
-  MOZ_ASSERT(!mRunLoopSource, "IOPS Notification Loop Source already set up. "
-                              "(StopListening should have been called)");
-
-  mRunLoopSource = ::IOPSNotificationCreateRunLoopSource(HandleChange, this);
-  if (mRunLoopSource) {
-    ::CFRunLoopAddSource(::CFRunLoopGetCurrent(), mRunLoopSource,
-                         kCFRunLoopDefaultMode);
-
-    // Invoke our callback now so we have data if GetCurrentBatteryInformation is
-    // called before a change happens.
-    HandleChange(this);
-    mShouldNotify = true;
-  }
-}
-
-void
-MacPowerInformationService::StopListening()
-{
-  MOZ_ASSERT(mRunLoopSource, "IOPS Notification Loop Source not set up. "
-                             "(StopListening without BeginListening)");
-
-  ::CFRunLoopRemoveSource(::CFRunLoopGetCurrent(), mRunLoopSource,
-                          kCFRunLoopDefaultMode);
-  mRunLoopSource = nullptr;
-}
-
-void
-MacPowerInformationService::HandleChange(void* aContext) {
-  MacPowerInformationService* power =
-    static_cast<MacPowerInformationService*>(aContext);
-
-  CFTypeRef data = ::IOPSCopyPowerSourcesInfo();
-  if (!data) {
-    ::CFRelease(data);
-    return;
-  }
-
-  // Get the list of power sources.
-  CFArrayRef list = ::IOPSCopyPowerSourcesList(data);
-  if (!list) {
-    ::CFRelease(list);
-    return;
-  }
-
-  // Default values. These will be used if there are 0 sources or we can't find
-  // better information.
-  double level = kDefaultLevel;
-  double charging = kDefaultCharging;
-  double remainingTime = kDefaultRemainingTime;
-
-  // Look for the first battery power source to give us the information we need.
-  // Usually there's only 1 available, depending on current power source.
-  for (CFIndex i = 0; i < ::CFArrayGetCount(list); ++i) {
-    CFTypeRef source = ::CFArrayGetValueAtIndex(list, i);
-    CFDictionaryRef currPowerSourceDesc = ::IOPSGetPowerSourceDescription(data, source);
-    if (!currPowerSourceDesc) {
-      continue;
-    }
-
-    // Get a battery level estimate. This key is required.
-    int currentCapacity = 0;
-    const void* cfRef = ::CFDictionaryGetValue(currPowerSourceDesc, CFSTR(kIOPSCurrentCapacityKey));
-    ::CFNumberGetValue((CFNumberRef)cfRef, kCFNumberSInt32Type, &currentCapacity);
-
-    // This key is also required.
-    int maxCapacity = 0;
-    cfRef = ::CFDictionaryGetValue(currPowerSourceDesc, CFSTR(kIOPSMaxCapacityKey));
-    ::CFNumberGetValue((CFNumberRef)cfRef, kCFNumberSInt32Type, &maxCapacity);
-
-    if (maxCapacity > 0) {
-      level = static_cast<double>(currentCapacity)/static_cast<double>(maxCapacity);
-    }
-
-    // Find out if we're charging.
-    // This key is optional, we fallback to kDefaultCharging if the current power
-    // source doesn't have that info.
-    if(::CFDictionaryGetValueIfPresent(currPowerSourceDesc, CFSTR(kIOPSIsChargingKey), &cfRef)) {
-      charging = ::CFBooleanGetValue((CFBooleanRef)cfRef);
-
-      // Get an estimate of how long it's going to take until we're fully charged.
-      // This key is optional.
-      if (charging) {
-        // Default value that will be changed if we happen to find the actual
-        // remaining time.
-        remainingTime = level == 1.0 ? kDefaultRemainingTime : kUnknownRemainingTime;
-
-        if (::CFDictionaryGetValueIfPresent(currPowerSourceDesc,
-                CFSTR(kIOPSTimeToFullChargeKey), &cfRef)) {
-          int timeToCharge;
-          ::CFNumberGetValue((CFNumberRef)cfRef, kCFNumberIntType, &timeToCharge);
-          if (timeToCharge != kIOPSTimeRemainingUnknown) {
-            remainingTime = timeToCharge*60;
-          }
-        }
-      } else if (sIOPSGetTimeRemainingEstimate) { // not charging
-        // See if we can get a time estimate.
-        CFTimeInterval estimate = sIOPSGetTimeRemainingEstimate();
-        if (estimate == kIOPSTimeRemainingUnlimited || estimate == kIOPSTimeRemainingUnknown) {
-          remainingTime = kUnknownRemainingTime;
-        } else {
-          remainingTime = estimate;
-        }
-      }
-    }
-
-    break;
-  }
-
-  bool isNewData = level != power->mLevel || charging != power->mCharging ||
-                   remainingTime != power->mRemainingTime;
-
-  power->mRemainingTime = remainingTime;
-  power->mCharging = charging;
-  power->mLevel = level;
-
-  // Notify the observers if stuff changed.
-  if (power->mShouldNotify && isNewData) {
-    hal::NotifyBatteryChange(hal::BatteryInformation(power->mLevel,
-                                                     power->mCharging,
-                                                     power->mRemainingTime));
-  }
-
-  ::CFRelease(data);
-  ::CFRelease(list);
-}
-
-} // namespace hal_impl
-} // namespace mozilla
diff --git a/hal/fallback/FallbackBattery.cpp b/hal/fallback/FallbackBattery.cpp
deleted file mode 100644
index 3e5e71574..000000000
--- a/hal/fallback/FallbackBattery.cpp
+++ /dev/null
@@ -1,30 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set sw=2 ts=8 et ft=cpp : */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this file,
- * You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include "Hal.h"
-#include "mozilla/dom/battery/Constants.h"
-
-namespace mozilla {
-namespace hal_impl {
-
-void
-EnableBatteryNotifications()
-{}
-
-void
-DisableBatteryNotifications()
-{}
-
-void
-GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo)
-{
-  aBatteryInfo->level() = dom::battery::kDefaultLevel;
-  aBatteryInfo->charging() = dom::battery::kDefaultCharging;
-  aBatteryInfo->remainingTime() = dom::battery::kDefaultRemainingTime;
-}
-
-} // hal_impl
-} // namespace mozilla
diff --git a/hal/linux/UPowerClient.cpp b/hal/linux/UPowerClient.cpp
deleted file mode 100644
index 9f6e04379..000000000
--- a/hal/linux/UPowerClient.cpp
+++ /dev/null
@@ -1,508 +0,0 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include "Hal.h"
-#include "HalLog.h"
-#include <dbus/dbus-glib.h>
-#include <dbus/dbus-glib-lowlevel.h>
-#include <mozilla/Attributes.h>
-#include <mozilla/dom/battery/Constants.h>
-#include "nsAutoRef.h"
-#include <cmath>
-
-/*
- * Helper that manages the destruction of glib objects as soon as they leave
- * the current scope.
- *
- * We are specializing nsAutoRef class.
- */
-
-template <>
-class nsAutoRefTraits<GHashTable> : public nsPointerRefTraits<GHashTable>
-{
-public:
-  static void Release(GHashTable* ptr) { g_hash_table_unref(ptr); }
-};
-
-using namespace mozilla::dom::battery;
-
-namespace mozilla {
-namespace hal_impl {
-
-/**
- * This is the declaration of UPowerClient class. This class is listening and
- * communicating to upower daemon through DBus.
- * There is no header file because this class shouldn't be public.
- */
-class UPowerClient
-{
-public:
-  static UPowerClient* GetInstance();
-
-  void BeginListening();
-  void StopListening();
-
-  double GetLevel();
-  bool   IsCharging();
-  double GetRemainingTime();
-
-  ~UPowerClient();
-
-private:
-  UPowerClient();
-
-  enum States {
-    eState_Unknown = 0,
-    eState_Charging,
-    eState_Discharging,
-    eState_Empty,
-    eState_FullyCharged,
-    eState_PendingCharge,
-    eState_PendingDischarge
-  };
-
-  /**
-   * Update the currently tracked device.
-   * @return whether everything went ok.
-   */
-  void UpdateTrackedDeviceSync();
-
-  /**
-   * Returns a hash table with the properties of aDevice.
-   * Note: the caller has to unref the hash table.
-   */
-  GHashTable* GetDevicePropertiesSync(DBusGProxy* aProxy);
-  void GetDevicePropertiesAsync(DBusGProxy* aProxy);
-  static void GetDevicePropertiesCallback(DBusGProxy* aProxy,
-                                          DBusGProxyCall* aCall,
-                                          void* aData);
-
-  /**
-   * Using the device properties (aHashTable), this method updates the member
-   * variable storing the values we care about.
-   */
-  void UpdateSavedInfo(GHashTable* aHashTable);
-
-  /**
-   * Callback used by 'DeviceChanged' signal.
-   */
-  static void DeviceChanged(DBusGProxy* aProxy, const gchar* aObjectPath,
-                            UPowerClient* aListener);
-
-  /**
-   * Callback used by 'PropertiesChanged' signal.
-   * This method is called when the the battery level changes.
-   * (Only with upower >= 0.99)
-   */
-  static void PropertiesChanged(DBusGProxy* aProxy, const gchar*,
-                                GHashTable*, char**,
-                                UPowerClient* aListener);
-
-  /**
-   * Callback called when mDBusConnection gets a signal.
-   */
-  static DBusHandlerResult ConnectionSignalFilter(DBusConnection* aConnection,
-                                                  DBusMessage* aMessage,
-                                                  void* aData);
-
-  // The DBus connection object.
-  DBusGConnection* mDBusConnection;
-
-  // The DBus proxy object to upower.
-  DBusGProxy* mUPowerProxy;
-
-  // The path of the tracked device.
-  gchar* mTrackedDevice;
-
-  // The DBusGProxy for the tracked device.
-  DBusGProxy* mTrackedDeviceProxy;
-
-  double mLevel;
-  bool mCharging;
-  double mRemainingTime;
-
-  static UPowerClient* sInstance;
-
-  static const guint sDeviceTypeBattery = 2;
-  static const guint64 kUPowerUnknownRemainingTime = 0;
-};
-
-/*
- * Implementation of mozilla::hal_impl::EnableBatteryNotifications,
- *                   mozilla::hal_impl::DisableBatteryNotifications,
- *               and mozilla::hal_impl::GetCurrentBatteryInformation.
- */
-
-void
-EnableBatteryNotifications()
-{
-  UPowerClient::GetInstance()->BeginListening();
-}
-
-void
-DisableBatteryNotifications()
-{
-  UPowerClient::GetInstance()->StopListening();
-}
-
-void
-GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo)
-{
-  UPowerClient* upowerClient = UPowerClient::GetInstance();
-
-  aBatteryInfo->level() = upowerClient->GetLevel();
-  aBatteryInfo->charging() = upowerClient->IsCharging();
-  aBatteryInfo->remainingTime() = upowerClient->GetRemainingTime();
-}
-
-/*
- * Following is the implementation of UPowerClient.
- */
-
-UPowerClient* UPowerClient::sInstance = nullptr;
-
-/* static */ UPowerClient*
-UPowerClient::GetInstance()
-{
-  if (!sInstance) {
-    sInstance = new UPowerClient();
-  }
-
-  return sInstance;
-}
-
-UPowerClient::UPowerClient()
-  : mDBusConnection(nullptr)
-  , mUPowerProxy(nullptr)
-  , mTrackedDevice(nullptr)
-  , mTrackedDeviceProxy(nullptr)
-  , mLevel(kDefaultLevel)
-  , mCharging(kDefaultCharging)
-  , mRemainingTime(kDefaultRemainingTime)
-{
-}
-
-UPowerClient::~UPowerClient()
-{
-  NS_ASSERTION(!mDBusConnection && !mUPowerProxy && !mTrackedDevice && !mTrackedDeviceProxy,
-               "The observers have not been correctly removed! "
-               "(StopListening should have been called)");
-}
-
-void
-UPowerClient::BeginListening()
-{
-  GError* error = nullptr;
-  mDBusConnection = dbus_g_bus_get(DBUS_BUS_SYSTEM, &error);
-
-  if (!mDBusConnection) {
-    HAL_LOG("Failed to open connection to bus: %s\n", error->message);
-    g_error_free(error);
-    return;
-  }
-
-  DBusConnection* dbusConnection =
-    dbus_g_connection_get_connection(mDBusConnection);
-
-  // Make sure we do not exit the entire program if DBus connection get lost.
-  dbus_connection_set_exit_on_disconnect(dbusConnection, false);
-
-  // Listening to signals the DBus connection is going to get so we will know
-  // when it is lost and we will be able to disconnect cleanly.
-  dbus_connection_add_filter(dbusConnection, ConnectionSignalFilter, this,
-                             nullptr);
-
-  mUPowerProxy = dbus_g_proxy_new_for_name(mDBusConnection,
-                                           "org.freedesktop.UPower",
-                                           "/org/freedesktop/UPower",
-                                           "org.freedesktop.UPower");
-
-  UpdateTrackedDeviceSync();
-
-  /*
-   * TODO: we should probably listen to DeviceAdded and DeviceRemoved signals.
-   * If we do that, we would have to disconnect from those in StopListening.
-   * It's not yet implemented because it requires testing hot plugging and
-   * removal of a battery.
-   */
-  dbus_g_proxy_add_signal(mUPowerProxy, "DeviceChanged", G_TYPE_STRING,
-                          G_TYPE_INVALID);
-  dbus_g_proxy_connect_signal(mUPowerProxy, "DeviceChanged",
-                              G_CALLBACK (DeviceChanged), this, nullptr);
-}
-
-void
-UPowerClient::StopListening()
-{
-  // If mDBusConnection isn't initialized, that means we are not really listening.
-  if (!mDBusConnection) {
-    return;
-  }
-
-  dbus_connection_remove_filter(
-      dbus_g_connection_get_connection(mDBusConnection),
-      ConnectionSignalFilter, this);
-
-  dbus_g_proxy_disconnect_signal(mUPowerProxy, "DeviceChanged",
-                                 G_CALLBACK (DeviceChanged), this);
-
-  g_free(mTrackedDevice);
-  mTrackedDevice = nullptr;
-
-  if (mTrackedDeviceProxy) {
-    dbus_g_proxy_disconnect_signal(mTrackedDeviceProxy, "PropertiesChanged",
-                                   G_CALLBACK (PropertiesChanged), this);
-
-    g_object_unref(mTrackedDeviceProxy);
-    mTrackedDeviceProxy = nullptr;
-  }
-
-  g_object_unref(mUPowerProxy);
-  mUPowerProxy = nullptr;
-
-  dbus_g_connection_unref(mDBusConnection);
-  mDBusConnection = nullptr;
-
-  // We should now show the default values, not the latest we got.
-  mLevel = kDefaultLevel;
-  mCharging = kDefaultCharging;
-  mRemainingTime = kDefaultRemainingTime;
-}
-
-void
-UPowerClient::UpdateTrackedDeviceSync()
-{
-  GType typeGPtrArray = dbus_g_type_get_collection("GPtrArray",
-                                                   DBUS_TYPE_G_OBJECT_PATH);
-  GPtrArray* devices = nullptr;
-  GError* error = nullptr;
-
-  // Reset the current tracked device:
-  g_free(mTrackedDevice);
-  mTrackedDevice = nullptr;
-
-  // Reset the current tracked device proxy:
-  if (mTrackedDeviceProxy) {
-    dbus_g_proxy_disconnect_signal(mTrackedDeviceProxy, "PropertiesChanged",
-                                   G_CALLBACK (PropertiesChanged), this);
-
-    g_object_unref(mTrackedDeviceProxy);
-    mTrackedDeviceProxy = nullptr;
-  }
-
-  // If that fails, that likely means upower isn't installed.
-  if (!dbus_g_proxy_call(mUPowerProxy, "EnumerateDevices", &error, G_TYPE_INVALID,
-                         typeGPtrArray, &devices, G_TYPE_INVALID)) {
-    HAL_LOG("Error: %s\n", error->message);
-    g_error_free(error);
-    return;
-  }
-
-  /*
-   * We are looking for the first device that is a battery.
-   * TODO: we could try to combine more than one battery.
-   */
-  for (guint i=0; i<devices->len; ++i) {
-    gchar* devicePath = static_cast<gchar*>(g_ptr_array_index(devices, i));
-
-    DBusGProxy* proxy = dbus_g_proxy_new_from_proxy(mUPowerProxy,
-                                                    "org.freedesktop.DBus.Properties",
-                                                    devicePath);
-
-    nsAutoRef<GHashTable> hashTable(GetDevicePropertiesSync(proxy));
-
-    if (g_value_get_uint(static_cast<const GValue*>(g_hash_table_lookup(hashTable, "Type"))) == sDeviceTypeBattery) {
-      UpdateSavedInfo(hashTable);
-      mTrackedDevice = devicePath;
-      mTrackedDeviceProxy = proxy;
-      break;
-    }
-
-    g_object_unref(proxy);
-    g_free(devicePath);
-  }
-
-  if (mTrackedDeviceProxy) {
-    dbus_g_proxy_add_signal(mTrackedDeviceProxy, "PropertiesChanged",
-                            G_TYPE_STRING,
-                            dbus_g_type_get_map("GHashTable", G_TYPE_STRING,
-                                                G_TYPE_VALUE),
-                            G_TYPE_STRV, G_TYPE_INVALID);
-    dbus_g_proxy_connect_signal(mTrackedDeviceProxy, "PropertiesChanged",
-                                G_CALLBACK (PropertiesChanged), this, nullptr);
-  }
-
-  g_ptr_array_free(devices, true);
-}
-
-/* static */ void
-UPowerClient::DeviceChanged(DBusGProxy* aProxy, const gchar* aObjectPath,
-                            UPowerClient* aListener)
-{
-  if (!aListener->mTrackedDevice) {
-    return;
-  }
-
-#if GLIB_MAJOR_VERSION >= 2 && GLIB_MINOR_VERSION >= 16
-  if (g_strcmp0(aObjectPath, aListener->mTrackedDevice)) {
-#else
-  if (g_ascii_strcasecmp(aObjectPath, aListener->mTrackedDevice)) {
-#endif
-    return;
-  }
-
-  aListener->GetDevicePropertiesAsync(aListener->mTrackedDeviceProxy);
-}
-
-/* static */ void
-UPowerClient::PropertiesChanged(DBusGProxy* aProxy, const gchar*, GHashTable*,
-                                char**, UPowerClient* aListener)
-{
-  aListener->GetDevicePropertiesAsync(aListener->mTrackedDeviceProxy);
-}
-
-/* static */ DBusHandlerResult
-UPowerClient::ConnectionSignalFilter(DBusConnection* aConnection,
-                                     DBusMessage* aMessage, void* aData)
-{
-  if (dbus_message_is_signal(aMessage, DBUS_INTERFACE_LOCAL, "Disconnected")) {
-    static_cast<UPowerClient*>(aData)->StopListening();
-    // We do not return DBUS_HANDLER_RESULT_HANDLED here because the connection
-    // might be shared and some other filters might want to do something.
-  }
-
-  return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
-}
-
-GHashTable*
-UPowerClient::GetDevicePropertiesSync(DBusGProxy* aProxy)
-{
-  GError* error = nullptr;
-  GHashTable* hashTable = nullptr;
-  GType typeGHashTable = dbus_g_type_get_map("GHashTable", G_TYPE_STRING,
-                                            G_TYPE_VALUE);
-  if (!dbus_g_proxy_call(aProxy, "GetAll", &error, G_TYPE_STRING,
-                         "org.freedesktop.UPower.Device", G_TYPE_INVALID,
-                         typeGHashTable, &hashTable, G_TYPE_INVALID)) {
-    HAL_LOG("Error: %s\n", error->message);
-    g_error_free(error);
-    return nullptr;
-  }
-
-  return hashTable;
-}
-
-/* static */ void
-UPowerClient::GetDevicePropertiesCallback(DBusGProxy* aProxy,
-                                          DBusGProxyCall* aCall, void* aData)
-{
-  GError* error = nullptr;
-  GHashTable* hashTable = nullptr;
-  GType typeGHashTable = dbus_g_type_get_map("GHashTable", G_TYPE_STRING,
-                                             G_TYPE_VALUE);
-  if (!dbus_g_proxy_end_call(aProxy, aCall, &error, typeGHashTable,
-                             &hashTable, G_TYPE_INVALID)) {
-    HAL_LOG("Error: %s\n", error->message);
-    g_error_free(error);
-  } else {
-    sInstance->UpdateSavedInfo(hashTable);
-    hal::NotifyBatteryChange(hal::BatteryInformation(sInstance->mLevel,
-                                                     sInstance->mCharging,
-                                                     sInstance->mRemainingTime));
-    g_hash_table_unref(hashTable);
-  }
-}
-
-void
-UPowerClient::GetDevicePropertiesAsync(DBusGProxy* aProxy)
-{
-  dbus_g_proxy_begin_call(aProxy, "GetAll", GetDevicePropertiesCallback, nullptr,
-                          nullptr, G_TYPE_STRING,
-                          "org.freedesktop.UPower.Device", G_TYPE_INVALID);
-}
-
-void
-UPowerClient::UpdateSavedInfo(GHashTable* aHashTable)
-{
-  bool isFull = false;
-
-  /*
-   * State values are confusing...
-   * First of all, after looking at upower sources (0.9.13), it seems that
-   * PendingDischarge and PendingCharge are not used.
-   * In addition, FullyCharged and Empty states are not clear because we do not
-   * know if the battery is actually charging or not. Those values come directly
-   * from sysfs (in the Linux kernel) which have four states: "Empty", "Full",
-   * "Charging" and "Discharging". In sysfs, "Empty" and "Full" are also only
-   * related to the level, not to the charging state.
-   * In this code, we are going to assume that Full means charging and Empty
-   * means discharging because if that is not the case, the state should not
-   * last a long time (actually, it should disappear at the following update).
-   * It might be even very hard to see real cases where the state is Empty and
-   * the battery is charging or the state is Full and the battery is discharging
-   * given that plugging/unplugging the battery should have an impact on the
-   * level.
-   */
-  switch (g_value_get_uint(static_cast<const GValue*>(g_hash_table_lookup(aHashTable, "State")))) {
-    case eState_Unknown:
-      mCharging = kDefaultCharging;
-      break;
-    case eState_FullyCharged:
-      isFull = true;
-      MOZ_FALLTHROUGH;
-    case eState_Charging:
-    case eState_PendingCharge:
-      mCharging = true;
-      break;
-    case eState_Discharging:
-    case eState_Empty:
-    case eState_PendingDischarge:
-      mCharging = false;
-      break;
-  }
-
-  /*
-   * The battery level might be very close to 100% (like 99%) without
-   * increasing. It seems that upower sets the battery state as 'full' in that
-   * case so we should trust it and not even try to get the value.
-   */
-  if (isFull) {
-    mLevel = 1.0;
-  } else {
-    mLevel = round(g_value_get_double(static_cast<const GValue*>(g_hash_table_lookup(aHashTable, "Percentage"))))*0.01;
-  }
-
-  if (isFull) {
-    mRemainingTime = 0;
-  } else {
-    mRemainingTime = mCharging ? g_value_get_int64(static_cast<const GValue*>(g_hash_table_lookup(aHashTable, "TimeToFull")))
-                               : g_value_get_int64(static_cast<const GValue*>(g_hash_table_lookup(aHashTable, "TimeToEmpty")));
-
-    if (mRemainingTime == kUPowerUnknownRemainingTime) {
-      mRemainingTime = kUnknownRemainingTime;
-    }
-  }
-}
-
-double
-UPowerClient::GetLevel()
-{
-  return mLevel;
-}
-
-bool
-UPowerClient::IsCharging()
-{
-  return mCharging;
-}
-
-double
-UPowerClient::GetRemainingTime()
-{
-  return mRemainingTime;
-}
-
-} // namespace hal_impl
-} // namespace mozilla
diff --git a/hal/moz.build b/hal/moz.build
index a1acfa320..d817e4a01 100644
--- a/hal/moz.build
+++ b/hal/moz.build
@@ -34,14 +34,6 @@ if CONFIG['OS_TARGET'] == 'Linux':
         'linux/LinuxMemory.cpp',
         'linux/LinuxPower.cpp',
     ]
-    if CONFIG['MOZ_ENABLE_DBUS']:
-        UNIFIED_SOURCES += [
-            'linux/UPowerClient.cpp',
-        ]
-    else:
-        UNIFIED_SOURCES += [
-            'fallback/FallbackBattery.cpp',
-        ]
 elif CONFIG['OS_TARGET'] == 'WINNT':
     UNIFIED_SOURCES += [
         'fallback/FallbackAlarm.cpp',
@@ -51,13 +43,8 @@ elif CONFIG['OS_TARGET'] == 'WINNT':
         'fallback/FallbackVibration.cpp',
         'windows/WindowsSensor.cpp',
     ]
-    # WindowsBattery.cpp cannot be built in unified mode because it relies on HalImpl.h.
-    SOURCES += [
-        'windows/WindowsBattery.cpp',
-    ]
 elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa':
     UNIFIED_SOURCES += [
-        'cocoa/CocoaBattery.cpp',
         'fallback/FallbackAlarm.cpp',
         'fallback/FallbackMemory.cpp',
         'fallback/FallbackPower.cpp',
@@ -73,18 +60,9 @@ elif CONFIG['OS_TARGET'] in ('OpenBSD', 'NetBSD', 'FreeBSD', 'DragonFly'):
         'fallback/FallbackSensor.cpp',
         'fallback/FallbackVibration.cpp',
     ]
-    if CONFIG['MOZ_ENABLE_DBUS']:
-        UNIFIED_SOURCES += [
-            'linux/UPowerClient.cpp',
-        ]
-    else:
-        UNIFIED_SOURCES += [
-            'fallback/FallbackBattery.cpp',
-        ]
 else:
     UNIFIED_SOURCES += [
         'fallback/FallbackAlarm.cpp',
-        'fallback/FallbackBattery.cpp',
         'fallback/FallbackMemory.cpp',
         'fallback/FallbackPower.cpp',
         'fallback/FallbackScreenConfiguration.cpp',
diff --git a/hal/sandbox/PHal.ipdl b/hal/sandbox/PHal.ipdl
index 1af550aff..8701e1219 100644
--- a/hal/sandbox/PHal.ipdl
+++ b/hal/sandbox/PHal.ipdl
@@ -20,12 +20,6 @@ using PRTime from "prtime.h";
 namespace mozilla {
 
 namespace hal {
-struct BatteryInformation {
-  double level;
-  bool   charging;
-  double remainingTime;
-};
-
 struct SensorData {
   SensorType sensor;
   PRTime timestamp;
@@ -69,7 +63,6 @@ nested(upto inside_cpow) sync protocol PHal {
     manager PContent;
 
 child:
-    async NotifyBatteryChange(BatteryInformation aBatteryInfo);
     async NotifyNetworkChange(NetworkInformation aNetworkInfo);
     async NotifyWakeLockChange(WakeLockInformation aWakeLockInfo);
     async NotifyScreenConfigurationChange(ScreenConfiguration aScreenOrientation);
@@ -80,11 +73,6 @@ parent:
     async Vibrate(uint32_t[] pattern, uint64_t[] id, PBrowser browser);
     async CancelVibrate(uint64_t[] id, PBrowser browser);
 
-    async EnableBatteryNotifications();
-    async DisableBatteryNotifications();
-    sync GetCurrentBatteryInformation()
-      returns (BatteryInformation aBatteryInfo);
-
     async EnableNetworkNotifications();
     async DisableNetworkNotifications();
     sync GetCurrentNetworkInformation()
diff --git a/hal/sandbox/SandboxHal.cpp b/hal/sandbox/SandboxHal.cpp
index aeaeb724e..579f3b472 100644
--- a/hal/sandbox/SandboxHal.cpp
+++ b/hal/sandbox/SandboxHal.cpp
@@ -13,7 +13,6 @@
 #include "mozilla/hal_sandbox/PHalParent.h"
 #include "mozilla/dom/TabParent.h"
 #include "mozilla/dom/TabChild.h"
-#include "mozilla/dom/battery/Types.h"
 #include "mozilla/dom/network/Types.h"
 #include "mozilla/dom/ScreenOrientation.h"
 #include "mozilla/EnumeratedRange.h"
@@ -70,24 +69,6 @@ CancelVibrate(const WindowIdentifier &id)
 }
 
 void
-EnableBatteryNotifications()
-{
-  Hal()->SendEnableBatteryNotifications();
-}
-
-void
-DisableBatteryNotifications()
-{
-  Hal()->SendDisableBatteryNotifications();
-}
-
-void
-GetCurrentBatteryInformation(BatteryInformation* aBatteryInfo)
-{
-  Hal()->SendGetCurrentBatteryInformation(aBatteryInfo);
-}
-
-void
 EnableNetworkNotifications()
 {
   Hal()->SendEnableNetworkNotifications();
@@ -376,7 +357,6 @@ bool SystemServiceIsRunning(const char* aSvcName)
 }
 
 class HalParent : public PHalParent
-                , public BatteryObserver
                 , public NetworkObserver
                 , public ISensorObserver
                 , public WakeLockObserver
@@ -390,7 +370,6 @@ public:
   {
     // NB: you *must* unconditionally unregister your observer here,
     // if it *may* be registered below.
-    hal::UnregisterBatteryObserver(this);
     hal::UnregisterNetworkObserver(this);
     hal::UnregisterScreenConfigurationObserver(this);
     for (auto sensor : MakeEnumeratedRange(NUM_SENSOR_TYPE)) {
@@ -432,30 +411,6 @@ public:
   }
 
   virtual bool
-  RecvEnableBatteryNotifications() override {
-    // We give all content battery-status permission.
-    hal::RegisterBatteryObserver(this);
-    return true;
-  }
-
-  virtual bool
-  RecvDisableBatteryNotifications() override {
-    hal::UnregisterBatteryObserver(this);
-    return true;
-  }
-
-  virtual bool
-  RecvGetCurrentBatteryInformation(BatteryInformation* aBatteryInfo) override {
-    // We give all content battery-status permission.
-    hal::GetCurrentBatteryInformation(aBatteryInfo);
-    return true;
-  }
-
-  void Notify(const BatteryInformation& aBatteryInfo) override {
-    Unused << SendNotifyBatteryChange(aBatteryInfo);
-  }
-
-  virtual bool
   RecvEnableNetworkNotifications() override {
     // We give all content access to this network-status information.
     hal::RegisterNetworkObserver(this);
@@ -769,12 +724,6 @@ public:
   }
 
   virtual bool
-  RecvNotifyBatteryChange(const BatteryInformation& aBatteryInfo) override {
-    hal::NotifyBatteryChange(aBatteryInfo);
-    return true;
-  }
-
-  virtual bool
   RecvNotifySensorChange(const hal::SensorData &aSensorData) override;
 
   virtual bool
diff --git a/hal/windows/WindowsBattery.cpp b/hal/windows/WindowsBattery.cpp
deleted file mode 100644
index 520330242..000000000
--- a/hal/windows/WindowsBattery.cpp
+++ /dev/null
@@ -1,127 +0,0 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include "Hal.h"
-#include "HalImpl.h"
-#include "mozilla/Preferences.h"
-#include "mozilla/dom/battery/Constants.h"
-
-#include <windows.h>
-
-using namespace mozilla::dom::battery;
-
-namespace mozilla {
-namespace hal_impl {
-
-static HPOWERNOTIFY sPowerHandle = nullptr;
-static HPOWERNOTIFY sCapacityHandle = nullptr;
-static HWND sHWnd = nullptr;
-
-static
-LRESULT CALLBACK
-BatteryWindowProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
-  if (msg != WM_POWERBROADCAST || wParam != PBT_POWERSETTINGCHANGE) {
-    return DefWindowProc(hwnd, msg, wParam, lParam);
-  }
-
-  hal::BatteryInformation currentInfo;
-
-  // Since we need update remainingTime, we cannot use LPARAM.
-  hal_impl::GetCurrentBatteryInformation(&currentInfo);
-
-  hal::NotifyBatteryChange(currentInfo);
-  return TRUE;
-}
-
-void
-EnableBatteryNotifications()
-{
-  // Create custom window to watch battery event
-  // If we can get Gecko's window handle, this is unnecessary.
-
-  if (sHWnd == nullptr) {
-    WNDCLASSW wc;
-    HMODULE hSelf = GetModuleHandle(nullptr);
-
-    if (!GetClassInfoW(hSelf, L"MozillaBatteryClass", &wc)) {
-      ZeroMemory(&wc, sizeof(WNDCLASSW));
-      wc.hInstance = hSelf;
-      wc.lpfnWndProc = BatteryWindowProc;
-      wc.lpszClassName = L"MozillaBatteryClass";
-      RegisterClassW(&wc);
-    }
-
-    sHWnd = CreateWindowW(L"MozillaBatteryClass", L"Battery Watcher",
-                          0, 0, 0, 0, 0,
-                          nullptr, nullptr, hSelf, nullptr);
-  }
-
-  if (sHWnd == nullptr) {
-    return;
-  }
-
-  sPowerHandle =
-    RegisterPowerSettingNotification(sHWnd,
-                                     &GUID_ACDC_POWER_SOURCE,
-                                     DEVICE_NOTIFY_WINDOW_HANDLE);
-  sCapacityHandle =
-    RegisterPowerSettingNotification(sHWnd,
-                                     &GUID_BATTERY_PERCENTAGE_REMAINING,
-                                     DEVICE_NOTIFY_WINDOW_HANDLE);
-}
-
-void
-DisableBatteryNotifications()
-{
-  if (sPowerHandle) {
-    UnregisterPowerSettingNotification(sPowerHandle);
-    sPowerHandle = nullptr;
-  }
-
-  if (sCapacityHandle) {
-    UnregisterPowerSettingNotification(sCapacityHandle);
-    sCapacityHandle = nullptr;
-  }
-
-  if (sHWnd) {
-    DestroyWindow(sHWnd);
-    sHWnd = nullptr;
-  }
-}
-
-void
-GetCurrentBatteryInformation(hal::BatteryInformation* aBatteryInfo)
-{
-  SYSTEM_POWER_STATUS status;
-  if (!GetSystemPowerStatus(&status)) {
-    aBatteryInfo->level() = kDefaultLevel;
-    aBatteryInfo->charging() = kDefaultCharging;
-    aBatteryInfo->remainingTime() = kDefaultRemainingTime;
-    return;
-  }
-
-  aBatteryInfo->level() =
-    status.BatteryLifePercent == 255 ? kDefaultLevel
-                                     : ((double)status.BatteryLifePercent) / 100.0;
-  aBatteryInfo->charging() = (status.ACLineStatus != 0);
-  if (status.ACLineStatus != 0) {
-    if (aBatteryInfo->level() == 1.0) {
-      // GetSystemPowerStatus API may returns -1 for BatteryFullLifeTime.
-      // So, if battery is 100%, set kDefaultRemainingTime at force.
-      aBatteryInfo->remainingTime() = kDefaultRemainingTime;
-    } else {
-      aBatteryInfo->remainingTime() =
-        status.BatteryFullLifeTime == (DWORD)-1 ? kUnknownRemainingTime
-                                                : status.BatteryFullLifeTime;
-    }
-  } else {
-    aBatteryInfo->remainingTime() =
-      status.BatteryLifeTime == (DWORD)-1 ? kUnknownRemainingTime
-                                          : status.BatteryLifeTime;
-  }
-}
-
-} // hal_impl
-} // mozilla
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 90a178d9c..c8af46e1d 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -4731,15 +4731,10 @@ pref("dom.vibrator.enabled", true);
 pref("dom.vibrator.max_vibrate_ms", 10000);
 pref("dom.vibrator.max_vibrate_list_len", 128);
 
-// Battery API
-// Disabled by default to reduce private data exposure.
-pref("dom.battery.enabled", false);
-
 // Abort API
 pref("dom.abortController.enabled", true);
 
 // Push
-
 pref("dom.push.enabled", false);
 
 pref("dom.push.loglevel", "error");