Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

44 files changed, 8924 insertions, 0 deletions

diff --git a/dom/gamepad/Gamepad.cpp b/dom/gamepad/Gamepad.cpp
new file mode 100644
index 0000000000..f64bb7f4eb
--- /dev/null
+++ b/dom/gamepad/Gamepad.cpp
@@ -0,0 +1,188 @@
+/* -*- 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 "Gamepad.h"
+#include "nsPIDOMWindow.h"
+#include "nsTArray.h"
+#include "nsVariant.h"
+#include "mozilla/StaticPrefs_dom.h"
+#include "mozilla/dom/GamepadBinding.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(Gamepad)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(Gamepad)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(Gamepad)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(Gamepad, mParent, mButtons, mPose,
+                                      mHapticActuators, mLightIndicators,
+                                      mTouchEvents)
+
+void Gamepad::UpdateTimestamp() {
+  nsCOMPtr<nsPIDOMWindowInner> newWindow(do_QueryInterface(mParent));
+  if (newWindow) {
+    Performance* perf = newWindow->GetPerformance();
+    if (perf) {
+      mTimestamp = perf->Now();
+    }
+  }
+}
+
+Gamepad::Gamepad(nsISupports* aParent, const nsAString& aID, int32_t aIndex,
+                 GamepadHandle aHandle, GamepadMappingType aMapping,
+                 GamepadHand aHand, uint32_t aDisplayID, uint32_t aNumButtons,
+                 uint32_t aNumAxes, uint32_t aNumHaptics,
+                 uint32_t aNumLightIndicator, uint32_t aNumTouchEvents)
+    : mParent(aParent),
+      mID(aID),
+      mIndex(aIndex),
+      mHandle(aHandle),
+      mDisplayId(aDisplayID),
+      mTouchIdHashValue(0),
+      mMapping(aMapping),
+      mHand(aHand),
+      mConnected(true),
+      mButtons(aNumButtons),
+      mAxes(aNumAxes),
+      mTimestamp(0) {
+  for (unsigned i = 0; i < aNumButtons; i++) {
+    mButtons.InsertElementAt(i, new GamepadButton(mParent));
+  }
+  mAxes.InsertElementsAt(0, aNumAxes, 0.0f);
+  mPose = new GamepadPose(aParent);
+  for (uint32_t i = 0; i < aNumHaptics; ++i) {
+    mHapticActuators.AppendElement(
+        new GamepadHapticActuator(mParent, mHandle, i));
+  }
+  for (uint32_t i = 0; i < aNumLightIndicator; ++i) {
+    mLightIndicators.AppendElement(
+        new GamepadLightIndicator(mParent, mHandle, i));
+  }
+  for (uint32_t i = 0; i < aNumTouchEvents; ++i) {
+    mTouchEvents.AppendElement(new GamepadTouch(mParent));
+  }
+
+  // Mapping touchId(0) to touchIdHash(0) by default.
+  mTouchIdHash.InsertOrUpdate(0, mTouchIdHashValue);
+  ++mTouchIdHashValue;
+  UpdateTimestamp();
+}
+
+void Gamepad::SetIndex(int32_t aIndex) { mIndex = aIndex; }
+
+void Gamepad::SetConnected(bool aConnected) { mConnected = aConnected; }
+
+void Gamepad::SetButton(uint32_t aButton, bool aPressed, bool aTouched,
+                        double aValue) {
+  MOZ_ASSERT(aButton < mButtons.Length());
+  mButtons[aButton]->SetPressed(aPressed);
+  mButtons[aButton]->SetTouched(aTouched);
+  mButtons[aButton]->SetValue(aValue);
+  UpdateTimestamp();
+}
+
+void Gamepad::SetAxis(uint32_t aAxis, double aValue) {
+  MOZ_ASSERT(aAxis < mAxes.Length());
+  if (mAxes[aAxis] != aValue) {
+    mAxes[aAxis] = aValue;
+    Gamepad_Binding::ClearCachedAxesValue(this);
+  }
+  UpdateTimestamp();
+}
+
+void Gamepad::SetPose(const GamepadPoseState& aPose) {
+  mPose->SetPoseState(aPose);
+  UpdateTimestamp();
+}
+
+void Gamepad::SetLightIndicatorType(uint32_t aLightIndex,
+                                    GamepadLightIndicatorType aType) {
+  mLightIndicators[aLightIndex]->SetType(aType);
+  UpdateTimestamp();
+}
+
+void Gamepad::SetTouchEvent(uint32_t aTouchIndex,
+                            const GamepadTouchState& aTouch) {
+  if (aTouchIndex >= mTouchEvents.Length()) {
+    MOZ_CRASH("Touch index exceeds the event array.");
+    return;
+  }
+
+  // Handling cross-origin tracking.
+  GamepadTouchState touchState(aTouch);
+  touchState.touchId = mTouchIdHash.LookupOrInsertWith(
+      touchState.touchId, [&] { return mTouchIdHashValue++; });
+  mTouchEvents[aTouchIndex]->SetTouchState(touchState);
+  UpdateTimestamp();
+}
+
+void Gamepad::SetHand(GamepadHand aHand) { mHand = aHand; }
+
+void Gamepad::SyncState(Gamepad* aOther) {
+  if (mButtons.Length() != aOther->mButtons.Length() ||
+      mAxes.Length() != aOther->mAxes.Length()) {
+    return;
+  }
+
+  mConnected = aOther->mConnected;
+  for (uint32_t i = 0; i < mButtons.Length(); ++i) {
+    mButtons[i]->SetPressed(aOther->mButtons[i]->Pressed());
+    mButtons[i]->SetTouched(aOther->mButtons[i]->Touched());
+    mButtons[i]->SetValue(aOther->mButtons[i]->Value());
+  }
+
+  bool changed = false;
+  for (uint32_t i = 0; i < mAxes.Length(); ++i) {
+    changed = changed || (mAxes[i] != aOther->mAxes[i]);
+    mAxes[i] = aOther->mAxes[i];
+  }
+  if (changed) {
+    Gamepad_Binding::ClearCachedAxesValue(this);
+  }
+
+  if (StaticPrefs::dom_gamepad_extensions_enabled()) {
+    MOZ_ASSERT(aOther->GetPose());
+    mPose->SetPoseState(aOther->GetPose()->GetPoseState());
+    mHand = aOther->Hand();
+    for (uint32_t i = 0; i < mHapticActuators.Length(); ++i) {
+      mHapticActuators[i]->Set(aOther->mHapticActuators[i]);
+    }
+
+    if (StaticPrefs::dom_gamepad_extensions_lightindicator()) {
+      for (uint32_t i = 0; i < mLightIndicators.Length(); ++i) {
+        mLightIndicators[i]->Set(aOther->mLightIndicators[i]);
+      }
+    }
+    if (StaticPrefs::dom_gamepad_extensions_multitouch()) {
+      for (uint32_t i = 0; i < mTouchEvents.Length(); ++i) {
+        mTouchEvents[i]->Set(aOther->mTouchEvents[i]);
+      }
+    }
+  }
+
+  UpdateTimestamp();
+}
+
+already_AddRefed<Gamepad> Gamepad::Clone(nsISupports* aParent) {
+  RefPtr<Gamepad> out =
+      new Gamepad(aParent, mID, mIndex, mHandle, mMapping, mHand, mDisplayId,
+                  mButtons.Length(), mAxes.Length(), mHapticActuators.Length(),
+                  mLightIndicators.Length(), mTouchEvents.Length());
+  out->SyncState(this);
+  return out.forget();
+}
+
+/* virtual */
+JSObject* Gamepad::WrapObject(JSContext* aCx,
+                              JS::Handle<JSObject*> aGivenProto) {
+  return Gamepad_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/Gamepad.h b/dom/gamepad/Gamepad.h
new file mode 100644
index 0000000000..689ea7f6d2
--- /dev/null
+++ b/dom/gamepad/Gamepad.h
@@ -0,0 +1,145 @@
+/* -*- 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_gamepad_Gamepad_h
+#define mozilla_dom_gamepad_Gamepad_h
+
+#include "mozilla/dom/GamepadBinding.h"
+#include "mozilla/dom/GamepadButton.h"
+#include "mozilla/dom/GamepadHandle.h"
+#include "mozilla/dom/GamepadPose.h"
+#include "mozilla/dom/GamepadHapticActuator.h"
+#include "mozilla/dom/GamepadLightIndicator.h"
+#include "mozilla/dom/GamepadTouch.h"
+#include "mozilla/dom/Performance.h"
+#include <stdint.h>
+#include "nsCOMPtr.h"
+#include "nsTHashMap.h"
+#include "nsString.h"
+#include "nsTArray.h"
+#include "nsWrapperCache.h"
+
+namespace mozilla::dom {
+
+class GamepadHapticActuator;
+
+// Per spec:
+// https://dvcs.w3.org/hg/gamepad/raw-file/default/gamepad.html#remapping
+const int kStandardGamepadButtons = 17;
+const int kStandardGamepadAxes = 4;
+
+const int kButtonLeftTrigger = 6;
+const int kButtonRightTrigger = 7;
+
+const int kLeftStickXAxis = 0;
+const int kLeftStickYAxis = 1;
+const int kRightStickXAxis = 2;
+const int kRightStickYAxis = 3;
+
+class Gamepad final : public nsISupports, public nsWrapperCache {
+ public:
+  Gamepad(nsISupports* aParent, const nsAString& aID, int32_t aIndex,
+          GamepadHandle aHandle, GamepadMappingType aMapping, GamepadHand aHand,
+          uint32_t aDisplayID, uint32_t aNumButtons, uint32_t aNumAxes,
+          uint32_t aNumHaptics, uint32_t aNumLightIndicator,
+          uint32_t aNumTouchEvents);
+
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(Gamepad)
+
+  void SetConnected(bool aConnected);
+  void SetButton(uint32_t aButton, bool aPressed, bool aTouched, double aValue);
+  void SetAxis(uint32_t aAxis, double aValue);
+  void SetIndex(int32_t aIndex);
+  void SetPose(const GamepadPoseState& aPose);
+  void SetLightIndicatorType(uint32_t aLightIndex,
+                             GamepadLightIndicatorType aType);
+  void SetTouchEvent(uint32_t aTouchIndex, const GamepadTouchState& aTouch);
+  void SetHand(GamepadHand aHand);
+
+  // Make the state of this gamepad equivalent to other.
+  void SyncState(Gamepad* aOther);
+
+  // Return a new Gamepad containing the same data as this object,
+  // parented to aParent.
+  already_AddRefed<Gamepad> Clone(nsISupports* aParent);
+
+  nsISupports* GetParentObject() const { return mParent; }
+
+  virtual JSObject* WrapObject(JSContext* aCx,
+                               JS::Handle<JSObject*> aGivenProto) override;
+
+  void GetId(nsAString& aID) const { aID = mID; }
+
+  DOMHighResTimeStamp Timestamp() const { return mTimestamp; }
+
+  GamepadMappingType Mapping() { return mMapping; }
+
+  uint32_t DisplayId() const { return mDisplayId; }
+
+  GamepadHand Hand() { return mHand; }
+
+  bool Connected() const { return mConnected; }
+
+  int32_t Index() const { return mIndex; }
+
+  void GetButtons(nsTArray<RefPtr<GamepadButton>>& aButtons) const {
+    aButtons = mButtons.Clone();
+  }
+
+  void GetAxes(nsTArray<double>& aAxes) const { aAxes = mAxes.Clone(); }
+
+  GamepadPose* GetPose() const { return mPose; }
+
+  void GetHapticActuators(
+      nsTArray<RefPtr<GamepadHapticActuator>>& aHapticActuators) const {
+    aHapticActuators = mHapticActuators.Clone();
+  }
+
+  void GetLightIndicators(
+      nsTArray<RefPtr<GamepadLightIndicator>>& aLightIndicators) const {
+    aLightIndicators = mLightIndicators.Clone();
+  }
+
+  void GetTouchEvents(nsTArray<RefPtr<GamepadTouch>>& aTouchEvents) const {
+    aTouchEvents = mTouchEvents.Clone();
+  }
+
+  GamepadHandle GetHandle() const { return mHandle; }
+
+ private:
+  virtual ~Gamepad() = default;
+  void UpdateTimestamp();
+
+ protected:
+  nsCOMPtr<nsISupports> mParent;
+  nsString mID;
+  int32_t mIndex;
+  // the gamepad hash key in GamepadManager
+  GamepadHandle mHandle;
+  uint32_t mDisplayId;
+  uint32_t mTouchIdHashValue;
+  // The mapping in use.
+  GamepadMappingType mMapping;
+  GamepadHand mHand;
+
+  // true if this gamepad is currently connected.
+  bool mConnected;
+
+  // Current state of buttons, axes.
+  nsTArray<RefPtr<GamepadButton>> mButtons;
+  nsTArray<double> mAxes;
+  DOMHighResTimeStamp mTimestamp;
+  RefPtr<GamepadPose> mPose;
+  nsTArray<RefPtr<GamepadHapticActuator>> mHapticActuators;
+  nsTArray<RefPtr<GamepadLightIndicator>> mLightIndicators;
+  nsTArray<RefPtr<GamepadTouch>> mTouchEvents;
+  nsTHashMap<nsUint32HashKey, uint32_t> mTouchIdHash;
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_gamepad_Gamepad_h
diff --git a/dom/gamepad/GamepadButton.cpp b/dom/gamepad/GamepadButton.cpp
new file mode 100644
index 0000000000..3ee985af3c
--- /dev/null
+++ b/dom/gamepad/GamepadButton.cpp
@@ -0,0 +1,28 @@
+/* -*- 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 "mozilla/dom/GamepadButton.h"
+#include "mozilla/dom/GamepadBinding.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(GamepadButton)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(GamepadButton)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(GamepadButton)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(GamepadButton, mParent)
+
+/* virtual */
+JSObject* GamepadButton::WrapObject(JSContext* aCx,
+                                    JS::Handle<JSObject*> aGivenProto) {
+  return GamepadButton_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/GamepadButton.h b/dom/gamepad/GamepadButton.h
new file mode 100644
index 0000000000..74bde07fcf
--- /dev/null
+++ b/dom/gamepad/GamepadButton.h
@@ -0,0 +1,53 @@
+/* -*- 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_gamepad_GamepadButton_h
+#define mozilla_dom_gamepad_GamepadButton_h
+
+#include <stdint.h>
+#include "nsCOMPtr.h"
+#include "nsWrapperCache.h"
+
+namespace mozilla::dom {
+
+class GamepadButton : public nsISupports, public nsWrapperCache {
+ public:
+  explicit GamepadButton(nsISupports* aParent)
+      : mParent(aParent), mValue(0), mPressed(false), mTouched(false) {}
+
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(GamepadButton)
+
+  nsISupports* GetParentObject() const { return mParent; }
+
+  virtual JSObject* WrapObject(JSContext* aCx,
+                               JS::Handle<JSObject*> aGivenProto) override;
+
+  void SetPressed(bool aPressed) { mPressed = aPressed; }
+
+  void SetTouched(bool aTouched) { mTouched = aTouched; }
+
+  void SetValue(double aValue) { mValue = aValue; }
+
+  bool Pressed() const { return mPressed; }
+
+  bool Touched() const { return mTouched; }
+
+  double Value() const { return mValue; }
+
+ private:
+  virtual ~GamepadButton() = default;
+
+ protected:
+  nsCOMPtr<nsISupports> mParent;
+  double mValue;
+  bool mPressed;
+  bool mTouched;
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_gamepad_GamepadButton_h
diff --git a/dom/gamepad/GamepadHandle.cpp b/dom/gamepad/GamepadHandle.cpp
new file mode 100644
index 0000000000..0357975a71
--- /dev/null
+++ b/dom/gamepad/GamepadHandle.cpp
@@ -0,0 +1,40 @@
+/* -*- 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 "GamepadHandle.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/HashFunctions.h"
+
+namespace mozilla::dom {
+
+GamepadHandle::GamepadHandle(uint32_t aValue, GamepadHandleKind aKind)
+    : mValue(aValue), mKind(aKind) {
+  MOZ_RELEASE_ASSERT(mValue);
+}
+
+GamepadHandleKind GamepadHandle::GetKind() const { return mKind; }
+
+PLDHashNumber GamepadHandle::Hash() const {
+  return HashGeneric(mValue, uint8_t(mKind));
+}
+
+bool operator==(const GamepadHandle& a, const GamepadHandle& b) {
+  return (a.mValue == b.mValue) && (a.mKind == b.mKind);
+}
+
+bool operator!=(const GamepadHandle& a, const GamepadHandle& b) {
+  return !(a == b);
+}
+
+bool operator<(const GamepadHandle& a, const GamepadHandle& b) {
+  if (a.mKind == b.mKind) {
+    return a.mValue < b.mValue;
+  }
+  // Arbitrarily order them by kind
+  return uint8_t(a.mKind) < uint8_t(b.mKind);
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/GamepadHandle.h b/dom/gamepad/GamepadHandle.h
new file mode 100644
index 0000000000..c13e2b912e
--- /dev/null
+++ b/dom/gamepad/GamepadHandle.h
@@ -0,0 +1,89 @@
+/* -*- 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/. */
+
+// This file defines a strongly-typed opaque gamepad handle
+//
+// The handle is designed to be copied around and passed over IPC. It keeps
+// track of which "provider" created the handle so it can ensure that
+// providers are never mixed. It also allows each provider to have its own
+// algorithm for generating gamepad IDs, since the VR and Platform services
+// do it differently.
+
+#ifndef mozilla_dom_gamepad_GamepadHandle_h
+#define mozilla_dom_gamepad_GamepadHandle_h
+
+#include "PLDHashTable.h"
+#include <type_traits>
+#include <cinttypes>
+
+namespace IPC {
+
+template <class>
+struct ParamTraits;
+
+}  // namespace IPC
+
+namespace mozilla::gfx {
+
+class VRDisplayClient;
+class VRManager;
+
+}  // namespace mozilla::gfx
+
+namespace mozilla::dom {
+
+class GamepadPlatformService;
+class GamepadServiceTest;
+class XRInputSource;
+
+// The "kind" of a gamepad handle is based on which provider created it
+enum class GamepadHandleKind : uint8_t {
+  GamepadPlatformManager,
+  VR,
+};
+
+class GamepadHandle {
+ public:
+  // Allow handle to be passed around as a simple object
+  GamepadHandle() = default;
+  GamepadHandle(const GamepadHandle&) = default;
+  GamepadHandle& operator=(const GamepadHandle&) = default;
+
+  // Helps code know which manager to send requests to
+  GamepadHandleKind GetKind() const;
+
+  // Define operators so the handle can compared and stored in maps
+  friend bool operator==(const GamepadHandle& a, const GamepadHandle& b);
+  friend bool operator!=(const GamepadHandle& a, const GamepadHandle& b);
+  friend bool operator<(const GamepadHandle& a, const GamepadHandle& b);
+
+  PLDHashNumber Hash() const;
+
+ private:
+  explicit GamepadHandle(uint32_t aValue, GamepadHandleKind aKind);
+  uint32_t GetValue() const { return mValue; }
+
+  uint32_t mValue{0};
+  GamepadHandleKind mKind{GamepadHandleKind::GamepadPlatformManager};
+
+  // These are the classes that are "gamepad managers". They are allowed to
+  // create new handles and inspect their actual value
+  friend class mozilla::dom::GamepadPlatformService;
+  friend class mozilla::dom::GamepadServiceTest;
+  friend class mozilla::dom::XRInputSource;
+  friend class mozilla::gfx::VRDisplayClient;
+  friend class mozilla::gfx::VRManager;
+
+  // Allow IPDL to serialize us
+  friend struct IPC::ParamTraits<mozilla::dom::GamepadHandle>;
+};
+
+static_assert(std::is_trivially_copyable<GamepadHandle>::value,
+              "GamepadHandle must be trivially copyable");
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_gamepad_GamepadHandle_h
diff --git a/dom/gamepad/GamepadHapticActuator.cpp b/dom/gamepad/GamepadHapticActuator.cpp
new file mode 100644
index 0000000000..462e386c8e
--- /dev/null
+++ b/dom/gamepad/GamepadHapticActuator.cpp
@@ -0,0 +1,80 @@
+/* -*- 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 "mozilla/dom/GamepadHapticActuator.h"
+#include "mozilla/dom/GamepadManager.h"
+#include "mozilla/dom/Promise.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(GamepadHapticActuator)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(GamepadHapticActuator)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(GamepadHapticActuator)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(GamepadHapticActuator, mParent)
+
+GamepadHapticActuator::GamepadHapticActuator(nsISupports* aParent,
+                                             GamepadHandle aGamepadHandle,
+                                             uint32_t aIndex)
+    : mParent(aParent),
+      mGamepadHandle(aGamepadHandle),
+      mType(GamepadHapticActuatorType::Vibration),
+      mIndex(aIndex) {}
+
+/* virtual */
+JSObject* GamepadHapticActuator::WrapObject(JSContext* aCx,
+                                            JS::Handle<JSObject*> aGivenProto) {
+  return GamepadHapticActuator_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+nsISupports* GamepadHapticActuator::GetParentObject() const { return mParent; }
+
+#define CLAMP(f, min, max) (((f) < min) ? min : (((f) > max) ? max : (f)))
+
+already_AddRefed<Promise> GamepadHapticActuator::Pulse(double aValue,
+                                                       double aDuration,
+                                                       ErrorResult& aRv) {
+  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(GetParentObject());
+  MOZ_ASSERT(global);
+
+  RefPtr<GamepadManager> gamepadManager(GamepadManager::GetService());
+  MOZ_ASSERT(gamepadManager);
+
+  // Clamp intensity aValue to be 0~1.
+  double value = CLAMP(aValue, 0, 1);
+  // aDuration should be always positive.
+  double duration = CLAMP(aDuration, 0, aDuration);
+
+  switch (mType) {
+    case GamepadHapticActuatorType::Vibration: {
+      RefPtr<Promise> promise = gamepadManager->VibrateHaptic(
+          mGamepadHandle, mIndex, value, duration, global, aRv);
+      if (!promise) {
+        return nullptr;
+      }
+      return promise.forget();
+    }
+    default: {
+      // We need to implement other types of haptic
+      MOZ_ASSERT(false);
+      return nullptr;
+    }
+  }
+}
+
+GamepadHapticActuatorType GamepadHapticActuator::Type() const { return mType; }
+
+void GamepadHapticActuator::Set(const GamepadHapticActuator* aOther) {
+  mGamepadHandle = aOther->mGamepadHandle;
+  mType = aOther->mType;
+  mIndex = aOther->mIndex;
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/GamepadHapticActuator.h b/dom/gamepad/GamepadHapticActuator.h
new file mode 100644
index 0000000000..18b659137b
--- /dev/null
+++ b/dom/gamepad/GamepadHapticActuator.h
@@ -0,0 +1,51 @@
+/* -*- 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_gamepad_GamepadHapticActuator_h
+#define mozilla_dom_gamepad_GamepadHapticActuator_h
+
+#include "nsCOMPtr.h"
+#include "nsWrapperCache.h"
+#include "mozilla/dom/GamepadHapticActuatorBinding.h"
+#include "mozilla/dom/Gamepad.h"
+#include "mozilla/dom/GamepadHandle.h"
+
+namespace mozilla::dom {
+class Promise;
+
+class GamepadHapticActuator : public nsISupports, public nsWrapperCache {
+ public:
+  GamepadHapticActuator(nsISupports* aParent, GamepadHandle aGamepadHandle,
+                        uint32_t aIndex);
+
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(GamepadHapticActuator)
+
+  nsISupports* GetParentObject() const;
+
+  virtual JSObject* WrapObject(JSContext* aCx,
+                               JS::Handle<JSObject*> aGivenProto) override;
+
+  already_AddRefed<Promise> Pulse(double aValue, double aDuration,
+                                  ErrorResult& aRv);
+
+  GamepadHapticActuatorType Type() const;
+
+  void Set(const GamepadHapticActuator* aOther);
+
+ private:
+  virtual ~GamepadHapticActuator() = default;
+
+ protected:
+  nsCOMPtr<nsISupports> mParent;
+  GamepadHandle mGamepadHandle;
+  GamepadHapticActuatorType mType;
+  uint32_t mIndex;
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_gamepad_GamepadHapticActuator_h
diff --git a/dom/gamepad/GamepadLightIndicator.cpp b/dom/gamepad/GamepadLightIndicator.cpp
new file mode 100644
index 0000000000..0ddb1bffe6
--- /dev/null
+++ b/dom/gamepad/GamepadLightIndicator.cpp
@@ -0,0 +1,69 @@
+/* -*- 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 "mozilla/dom/GamepadLightIndicator.h"
+#include "mozilla/dom/GamepadManager.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/HoldDropJSObjects.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(GamepadLightIndicator)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(GamepadLightIndicator)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(GamepadLightIndicator)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(GamepadLightIndicator, mParent)
+
+GamepadLightIndicator::GamepadLightIndicator(nsISupports* aParent,
+                                             GamepadHandle aGamepadHandle,
+                                             uint32_t aIndex)
+    : mParent(aParent),
+      mType(DefaultType()),
+      mGamepadHandle(aGamepadHandle),
+      mIndex(aIndex) {}
+
+GamepadLightIndicator::~GamepadLightIndicator() {
+  mozilla::DropJSObjects(this);
+}
+
+/* virtual */ JSObject* GamepadLightIndicator::WrapObject(
+    JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
+  return GamepadLightIndicator_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+nsISupports* GamepadLightIndicator::GetParentObject() const { return mParent; }
+
+already_AddRefed<Promise> GamepadLightIndicator::SetColor(
+    const GamepadLightColor& color, ErrorResult& aRv) {
+  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(GetParentObject());
+  MOZ_ASSERT(global);
+
+  RefPtr<GamepadManager> gamepadManager(GamepadManager::GetService());
+  MOZ_ASSERT(gamepadManager);
+
+  RefPtr<Promise> promise = gamepadManager->SetLightIndicatorColor(
+      mGamepadHandle, mIndex, color.mRed, color.mGreen, color.mBlue, global,
+      aRv);
+  if (!promise) {
+    return nullptr;
+  }
+  return promise.forget();
+}
+
+GamepadLightIndicatorType GamepadLightIndicator::Type() const { return mType; }
+
+void GamepadLightIndicator::Set(const GamepadLightIndicator* aOther) {
+  MOZ_ASSERT(aOther);
+  mGamepadHandle = aOther->mGamepadHandle;
+  mType = aOther->mType;
+  mIndex = aOther->mIndex;
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/GamepadLightIndicator.h b/dom/gamepad/GamepadLightIndicator.h
new file mode 100644
index 0000000000..80c6f9c13b
--- /dev/null
+++ b/dom/gamepad/GamepadLightIndicator.h
@@ -0,0 +1,53 @@
+/* -*- 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_gamepad_GamepadLightIndicator_h
+#define mozilla_dom_gamepad_GamepadLightIndicator_h
+
+#include "mozilla/dom/GamepadLightIndicatorBinding.h"
+#include "mozilla/dom/GamepadHandle.h"
+#include "nsWrapperCache.h"
+
+namespace mozilla::dom {
+
+class GamepadLightIndicator final : public nsISupports, public nsWrapperCache {
+ public:
+  GamepadLightIndicator(nsISupports* aParent, GamepadHandle aGamepadHandle,
+                        uint32_t aIndex);
+
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(GamepadLightIndicator)
+
+  static GamepadLightIndicatorType DefaultType() {
+    return GamepadLightIndicatorType::Rgb;
+  }
+
+  nsISupports* GetParentObject() const;
+
+  virtual JSObject* WrapObject(JSContext* aCx,
+                               JS::Handle<JSObject*> aGivenProto) override;
+
+  already_AddRefed<Promise> SetColor(const GamepadLightColor& color,
+                                     ErrorResult& aRv);
+
+  void SetType(GamepadLightIndicatorType aType) { mType = aType; }
+
+  GamepadLightIndicatorType Type() const;
+
+  void Set(const GamepadLightIndicator* aOther);
+
+ private:
+  virtual ~GamepadLightIndicator();
+
+  nsCOMPtr<nsISupports> mParent;
+  GamepadLightIndicatorType mType;
+  GamepadHandle mGamepadHandle;
+  uint32_t mIndex;
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_gamepad_GamepadLightIndicator_h
diff --git a/dom/gamepad/GamepadManager.cpp b/dom/gamepad/GamepadManager.cpp
new file mode 100644
index 0000000000..8d67670746
--- /dev/null
+++ b/dom/gamepad/GamepadManager.cpp
@@ -0,0 +1,662 @@
+/* -*- 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 "mozilla/dom/GamepadManager.h"
+
+#include "mozilla/dom/Gamepad.h"
+#include "mozilla/dom/GamepadAxisMoveEvent.h"
+#include "mozilla/dom/GamepadButtonEvent.h"
+#include "mozilla/dom/GamepadEvent.h"
+#include "mozilla/dom/GamepadEventChannelChild.h"
+#include "mozilla/dom/GamepadMonitoring.h"
+#include "mozilla/dom/Promise.h"
+
+#include "mozilla/ipc/BackgroundChild.h"
+#include "mozilla/ipc/PBackgroundChild.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/StaticPrefs_dom.h"
+#include "mozilla/StaticPtr.h"
+
+#include "nsContentUtils.h"
+#include "nsGlobalWindowInner.h"
+#include "nsIObserver.h"
+#include "nsIObserverService.h"
+#include "nsThreadUtils.h"
+#include "VRManagerChild.h"
+#include "mozilla/Services.h"
+#include "mozilla/Unused.h"
+
+#include <cstddef>
+
+using namespace mozilla::ipc;
+
+namespace mozilla::dom {
+
+namespace {
+
+const nsTArray<RefPtr<nsGlobalWindowInner>>::index_type NoIndex =
+    nsTArray<RefPtr<nsGlobalWindowInner>>::NoIndex;
+
+bool sShutdown = false;
+
+StaticRefPtr<GamepadManager> gGamepadManagerSingleton;
+
+// A threshold value of axis move to determine the first
+// intent.
+const float AXIS_FIRST_INTENT_THRESHOLD_VALUE = 0.1f;
+
+}  // namespace
+
+NS_IMPL_ISUPPORTS(GamepadManager, nsIObserver)
+
+GamepadManager::GamepadManager()
+    : mEnabled(false),
+      mNonstandardEventsEnabled(false),
+      mShuttingDown(false),
+      mPromiseID(0) {}
+
+nsresult GamepadManager::Init() {
+  mEnabled = StaticPrefs::dom_gamepad_enabled();
+  mNonstandardEventsEnabled =
+      StaticPrefs::dom_gamepad_non_standard_events_enabled();
+  nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+
+  if (NS_WARN_IF(!observerService)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsresult rv;
+  rv = observerService->AddObserver(this, NS_XPCOM_WILL_SHUTDOWN_OBSERVER_ID,
+                                    false);
+
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+GamepadManager::Observe(nsISupports* aSubject, const char* aTopic,
+                        const char16_t* aData) {
+  nsCOMPtr<nsIObserverService> observerService =
+      mozilla::services::GetObserverService();
+  if (observerService) {
+    observerService->RemoveObserver(this, NS_XPCOM_WILL_SHUTDOWN_OBSERVER_ID);
+  }
+  BeginShutdown();
+  return NS_OK;
+}
+
+void GamepadManager::StopMonitoring() {
+  if (mChannelChild) {
+    PGamepadEventChannelChild::Send__delete__(mChannelChild);
+    mChannelChild = nullptr;
+  }
+  if (gfx::VRManagerChild::IsCreated()) {
+    gfx::VRManagerChild* vm = gfx::VRManagerChild::Get();
+    vm->SendControllerListenerRemoved();
+  }
+  mGamepads.Clear();
+}
+
+void GamepadManager::BeginShutdown() {
+  mShuttingDown = true;
+  StopMonitoring();
+  // Don't let windows call back to unregister during shutdown
+  for (uint32_t i = 0; i < mListeners.Length(); i++) {
+    mListeners[i]->SetHasGamepadEventListener(false);
+  }
+  mListeners.Clear();
+  sShutdown = true;
+}
+
+void GamepadManager::AddListener(nsGlobalWindowInner* aWindow) {
+  MOZ_ASSERT(aWindow);
+  MOZ_ASSERT(NS_IsMainThread());
+
+  // IPDL child has not been created
+  if (!mChannelChild) {
+    PBackgroundChild* actor = BackgroundChild::GetOrCreateForCurrentThread();
+    if (NS_WARN_IF(!actor)) {
+      // We are probably shutting down.
+      return;
+    }
+
+    RefPtr<GamepadEventChannelChild> child(GamepadEventChannelChild::Create());
+    if (!actor->SendPGamepadEventChannelConstructor(child.get())) {
+      // We are probably shutting down.
+      return;
+    }
+
+    mChannelChild = child;
+
+    if (gfx::VRManagerChild::IsCreated()) {
+      // Construct VRManagerChannel and ask adding the connected
+      // VR controllers to GamepadManager
+      gfx::VRManagerChild* vm = gfx::VRManagerChild::Get();
+      vm->SendControllerListenerAdded();
+    }
+  }
+
+  if (!mEnabled || mShuttingDown ||
+      aWindow->ShouldResistFingerprinting(RFPTarget::Gamepad)) {
+    return;
+  }
+
+  if (mListeners.IndexOf(aWindow) != NoIndex) {
+    return;  // already exists
+  }
+
+  mListeners.AppendElement(aWindow);
+}
+
+void GamepadManager::RemoveListener(nsGlobalWindowInner* aWindow) {
+  MOZ_ASSERT(aWindow);
+
+  if (mShuttingDown) {
+    // Doesn't matter at this point. It's possible we're being called
+    // as a result of our own destructor here, so just bail out.
+    return;
+  }
+
+  if (mListeners.IndexOf(aWindow) == NoIndex) {
+    return;  // doesn't exist
+  }
+
+  for (const auto& key : mGamepads.Keys()) {
+    aWindow->RemoveGamepad(key);
+  }
+
+  mListeners.RemoveElement(aWindow);
+
+  if (mListeners.IsEmpty()) {
+    StopMonitoring();
+  }
+}
+
+already_AddRefed<Gamepad> GamepadManager::GetGamepad(
+    GamepadHandle aHandle) const {
+  RefPtr<Gamepad> gamepad;
+  if (mGamepads.Get(aHandle, getter_AddRefs(gamepad))) {
+    return gamepad.forget();
+  }
+
+  return nullptr;
+}
+
+void GamepadManager::AddGamepad(GamepadHandle aHandle, const nsAString& aId,
+                                GamepadMappingType aMapping, GamepadHand aHand,
+                                uint32_t aDisplayID, uint32_t aNumButtons,
+                                uint32_t aNumAxes, uint32_t aNumHaptics,
+                                uint32_t aNumLightIndicator,
+                                uint32_t aNumTouchEvents) {
+  // TODO: bug 852258: get initial button/axis state
+  RefPtr<Gamepad> newGamepad =
+      new Gamepad(nullptr, aId,
+                  0,  // index is set by global window
+                  aHandle, aMapping, aHand, aDisplayID, aNumButtons, aNumAxes,
+                  aNumHaptics, aNumLightIndicator, aNumTouchEvents);
+
+  // We store the gamepad related to its index given by the parent process,
+  // and no duplicate index is allowed.
+  MOZ_ASSERT(!mGamepads.Contains(aHandle));
+  mGamepads.InsertOrUpdate(aHandle, std::move(newGamepad));
+  NewConnectionEvent(aHandle, true);
+}
+
+void GamepadManager::RemoveGamepad(GamepadHandle aHandle) {
+  RefPtr<Gamepad> gamepad = GetGamepad(aHandle);
+  if (!gamepad) {
+    NS_WARNING("Trying to delete gamepad with invalid index");
+    return;
+  }
+  gamepad->SetConnected(false);
+  NewConnectionEvent(aHandle, false);
+  mGamepads.Remove(aHandle);
+}
+
+void GamepadManager::FireButtonEvent(EventTarget* aTarget, Gamepad* aGamepad,
+                                     uint32_t aButton, double aValue) {
+  nsString name =
+      aValue == 1.0L ? u"gamepadbuttondown"_ns : u"gamepadbuttonup"_ns;
+  GamepadButtonEventInit init;
+  init.mBubbles = false;
+  init.mCancelable = false;
+  init.mGamepad = aGamepad;
+  init.mButton = aButton;
+  RefPtr<GamepadButtonEvent> event =
+      GamepadButtonEvent::Constructor(aTarget, name, init);
+
+  event->SetTrusted(true);
+
+  aTarget->DispatchEvent(*event);
+}
+
+void GamepadManager::FireAxisMoveEvent(EventTarget* aTarget, Gamepad* aGamepad,
+                                       uint32_t aAxis, double aValue) {
+  GamepadAxisMoveEventInit init;
+  init.mBubbles = false;
+  init.mCancelable = false;
+  init.mGamepad = aGamepad;
+  init.mAxis = aAxis;
+  init.mValue = aValue;
+  RefPtr<GamepadAxisMoveEvent> event =
+      GamepadAxisMoveEvent::Constructor(aTarget, u"gamepadaxismove"_ns, init);
+
+  event->SetTrusted(true);
+
+  aTarget->DispatchEvent(*event);
+}
+
+void GamepadManager::NewConnectionEvent(GamepadHandle aHandle,
+                                        bool aConnected) {
+  if (mShuttingDown) {
+    return;
+  }
+
+  RefPtr<Gamepad> gamepad = GetGamepad(aHandle);
+  if (!gamepad) {
+    return;
+  }
+
+  // Hold on to listeners in a separate array because firing events
+  // can mutate the mListeners array.
+  nsTArray<RefPtr<nsGlobalWindowInner>> listeners(mListeners.Clone());
+
+  if (aConnected) {
+    for (uint32_t i = 0; i < listeners.Length(); i++) {
+#ifdef NIGHTLY_BUILD
+      // Don't fire a gamepadconnected event unless it's a secure context
+      if (!listeners[i]->IsSecureContext()) {
+        continue;
+      }
+#endif
+
+      // Do not fire gamepadconnected and gamepaddisconnected events when
+      // privacy.resistFingerprinting is true.
+      if (listeners[i]->ShouldResistFingerprinting(RFPTarget::Gamepad)) {
+        continue;
+      }
+
+      // Only send events to non-background windows
+      if (!listeners[i]->IsCurrentInnerWindow() ||
+          listeners[i]->GetOuterWindow()->IsBackground()) {
+        continue;
+      }
+
+      // We don't fire a connected event here unless the window
+      // has seen input from at least one device.
+      if (!listeners[i]->HasSeenGamepadInput()) {
+        continue;
+      }
+
+      SetWindowHasSeenGamepad(listeners[i], aHandle);
+
+      RefPtr<Gamepad> listenerGamepad = listeners[i]->GetGamepad(aHandle);
+      if (listenerGamepad) {
+        // Fire event
+        FireConnectionEvent(listeners[i], listenerGamepad, aConnected);
+      }
+    }
+  } else {
+    // For disconnection events, fire one at every window that has received
+    // data from this gamepad.
+    for (uint32_t i = 0; i < listeners.Length(); i++) {
+      // Even background windows get these events, so we don't have to
+      // deal with the hassle of syncing the state of removed gamepads.
+
+      // Do not fire gamepadconnected and gamepaddisconnected events when
+      // privacy.resistFingerprinting is true.
+      if (listeners[i]->ShouldResistFingerprinting(RFPTarget::Gamepad)) {
+        continue;
+      }
+
+      if (WindowHasSeenGamepad(listeners[i], aHandle)) {
+        RefPtr<Gamepad> listenerGamepad = listeners[i]->GetGamepad(aHandle);
+        if (listenerGamepad) {
+          listenerGamepad->SetConnected(false);
+          // Fire event
+          FireConnectionEvent(listeners[i], listenerGamepad, false);
+          listeners[i]->RemoveGamepad(aHandle);
+        }
+      }
+    }
+  }
+}
+
+void GamepadManager::FireConnectionEvent(EventTarget* aTarget,
+                                         Gamepad* aGamepad, bool aConnected) {
+  nsString name =
+      aConnected ? u"gamepadconnected"_ns : u"gamepaddisconnected"_ns;
+  GamepadEventInit init;
+  init.mBubbles = false;
+  init.mCancelable = false;
+  init.mGamepad = aGamepad;
+  RefPtr<GamepadEvent> event = GamepadEvent::Constructor(aTarget, name, init);
+
+  event->SetTrusted(true);
+
+  aTarget->DispatchEvent(*event);
+}
+
+void GamepadManager::SyncGamepadState(GamepadHandle aHandle,
+                                      nsGlobalWindowInner* aWindow,
+                                      Gamepad* aGamepad) {
+  if (mShuttingDown || !mEnabled ||
+      aWindow->ShouldResistFingerprinting(RFPTarget::Gamepad)) {
+    return;
+  }
+
+  RefPtr<Gamepad> gamepad = GetGamepad(aHandle);
+  if (!gamepad) {
+    return;
+  }
+
+  aGamepad->SyncState(gamepad);
+}
+
+// static
+bool GamepadManager::IsServiceRunning() { return !!gGamepadManagerSingleton; }
+
+// static
+already_AddRefed<GamepadManager> GamepadManager::GetService() {
+  if (sShutdown) {
+    return nullptr;
+  }
+
+  if (!gGamepadManagerSingleton) {
+    RefPtr<GamepadManager> manager = new GamepadManager();
+    nsresult rv = manager->Init();
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return nullptr;
+    }
+    gGamepadManagerSingleton = manager;
+    ClearOnShutdown(&gGamepadManagerSingleton);
+  }
+
+  RefPtr<GamepadManager> service(gGamepadManagerSingleton);
+  return service.forget();
+}
+
+bool GamepadManager::AxisMoveIsFirstIntent(nsGlobalWindowInner* aWindow,
+                                           GamepadHandle aHandle,
+                                           const GamepadChangeEvent& aEvent) {
+  const GamepadChangeEventBody& body = aEvent.body();
+  if (!WindowHasSeenGamepad(aWindow, aHandle) &&
+      body.type() == GamepadChangeEventBody::TGamepadAxisInformation) {
+    // Some controllers would send small axis values even they are just idle.
+    // To avoid controllers be activated without its first intent.
+    const GamepadAxisInformation& a = body.get_GamepadAxisInformation();
+    if (abs(a.value()) < AXIS_FIRST_INTENT_THRESHOLD_VALUE) {
+      return false;
+    }
+  }
+  return true;
+}
+
+bool GamepadManager::MaybeWindowHasSeenGamepad(nsGlobalWindowInner* aWindow,
+                                               GamepadHandle aHandle) {
+  if (!WindowHasSeenGamepad(aWindow, aHandle)) {
+    // This window hasn't seen this gamepad before, so
+    // send a connection event first.
+    SetWindowHasSeenGamepad(aWindow, aHandle);
+    return false;
+  }
+  return true;
+}
+
+bool GamepadManager::WindowHasSeenGamepad(nsGlobalWindowInner* aWindow,
+                                          GamepadHandle aHandle) const {
+  RefPtr<Gamepad> gamepad = aWindow->GetGamepad(aHandle);
+  return gamepad != nullptr;
+}
+
+void GamepadManager::SetWindowHasSeenGamepad(nsGlobalWindowInner* aWindow,
+                                             GamepadHandle aHandle,
+                                             bool aHasSeen) {
+  MOZ_ASSERT(aWindow);
+
+  if (mListeners.IndexOf(aWindow) == NoIndex) {
+    // This window isn't even listening for gamepad events.
+    return;
+  }
+
+  if (aHasSeen) {
+    aWindow->SetHasSeenGamepadInput(true);
+    nsCOMPtr<nsISupports> window = ToSupports(aWindow);
+    RefPtr<Gamepad> gamepad = GetGamepad(aHandle);
+    if (!gamepad) {
+      return;
+    }
+    RefPtr<Gamepad> clonedGamepad = gamepad->Clone(window);
+    aWindow->AddGamepad(aHandle, clonedGamepad);
+  } else {
+    aWindow->RemoveGamepad(aHandle);
+  }
+}
+
+void GamepadManager::Update(const GamepadChangeEvent& aEvent) {
+  if (!mEnabled || mShuttingDown) {
+    return;
+  }
+
+  const GamepadHandle handle = aEvent.handle();
+
+  GamepadChangeEventBody body = aEvent.body();
+
+  if (body.type() == GamepadChangeEventBody::TGamepadAdded) {
+    const GamepadAdded& a = body.get_GamepadAdded();
+    AddGamepad(handle, a.id(), static_cast<GamepadMappingType>(a.mapping()),
+               static_cast<GamepadHand>(a.hand()), a.display_id(),
+               a.num_buttons(), a.num_axes(), a.num_haptics(), a.num_lights(),
+               a.num_touches());
+    return;
+  }
+  if (body.type() == GamepadChangeEventBody::TGamepadRemoved) {
+    RemoveGamepad(handle);
+    return;
+  }
+
+  if (!SetGamepadByEvent(aEvent)) {
+    return;
+  }
+
+  // Hold on to listeners in a separate array because firing events
+  // can mutate the mListeners array.
+  nsTArray<RefPtr<nsGlobalWindowInner>> listeners(mListeners.Clone());
+
+  for (uint32_t i = 0; i < listeners.Length(); i++) {
+    // Only send events to non-background windows
+    if (!listeners[i]->IsCurrentInnerWindow() ||
+        listeners[i]->GetOuterWindow()->IsBackground() ||
+        listeners[i]->ShouldResistFingerprinting(RFPTarget::Gamepad)) {
+      continue;
+    }
+
+    SetGamepadByEvent(aEvent, listeners[i]);
+    MaybeConvertToNonstandardGamepadEvent(aEvent, listeners[i]);
+  }
+}
+
+void GamepadManager::MaybeConvertToNonstandardGamepadEvent(
+    const GamepadChangeEvent& aEvent, nsGlobalWindowInner* aWindow) {
+  MOZ_ASSERT(aWindow);
+
+  if (!mNonstandardEventsEnabled) {
+    return;
+  }
+
+  GamepadHandle handle = aEvent.handle();
+
+  RefPtr<Gamepad> gamepad = aWindow->GetGamepad(handle);
+  const GamepadChangeEventBody& body = aEvent.body();
+
+  if (gamepad) {
+    switch (body.type()) {
+      case GamepadChangeEventBody::TGamepadButtonInformation: {
+        const GamepadButtonInformation& a = body.get_GamepadButtonInformation();
+        FireButtonEvent(aWindow, gamepad, a.button(), a.value());
+        break;
+      }
+      case GamepadChangeEventBody::TGamepadAxisInformation: {
+        const GamepadAxisInformation& a = body.get_GamepadAxisInformation();
+        FireAxisMoveEvent(aWindow, gamepad, a.axis(), a.value());
+        break;
+      }
+      default:
+        break;
+    }
+  }
+}
+
+bool GamepadManager::SetGamepadByEvent(const GamepadChangeEvent& aEvent,
+                                       nsGlobalWindowInner* aWindow) {
+  bool ret = false;
+  bool firstTime = false;
+
+  GamepadHandle handle = aEvent.handle();
+
+  if (aWindow) {
+    if (!AxisMoveIsFirstIntent(aWindow, handle, aEvent)) {
+      return false;
+    }
+    firstTime = !MaybeWindowHasSeenGamepad(aWindow, handle);
+  }
+
+  RefPtr<Gamepad> gamepad =
+      aWindow ? aWindow->GetGamepad(handle) : GetGamepad(handle);
+  const GamepadChangeEventBody& body = aEvent.body();
+
+  if (gamepad) {
+    switch (body.type()) {
+      case GamepadChangeEventBody::TGamepadButtonInformation: {
+        const GamepadButtonInformation& a = body.get_GamepadButtonInformation();
+        gamepad->SetButton(a.button(), a.pressed(), a.touched(), a.value());
+        break;
+      }
+      case GamepadChangeEventBody::TGamepadAxisInformation: {
+        const GamepadAxisInformation& a = body.get_GamepadAxisInformation();
+        gamepad->SetAxis(a.axis(), a.value());
+        break;
+      }
+      case GamepadChangeEventBody::TGamepadPoseInformation: {
+        const GamepadPoseInformation& a = body.get_GamepadPoseInformation();
+        gamepad->SetPose(a.pose_state());
+        break;
+      }
+      case GamepadChangeEventBody::TGamepadLightIndicatorTypeInformation: {
+        const GamepadLightIndicatorTypeInformation& a =
+            body.get_GamepadLightIndicatorTypeInformation();
+        gamepad->SetLightIndicatorType(a.light(), a.type());
+        break;
+      }
+      case GamepadChangeEventBody::TGamepadTouchInformation: {
+        // Avoid GamepadTouch's touchId be accessed in cross-origin tracking.
+        for (uint32_t i = 0; i < mListeners.Length(); i++) {
+          RefPtr<Gamepad> listenerGamepad = mListeners[i]->GetGamepad(handle);
+          if (listenerGamepad && mListeners[i]->IsCurrentInnerWindow() &&
+              !mListeners[i]->GetOuterWindow()->IsBackground()) {
+            const GamepadTouchInformation& a =
+                body.get_GamepadTouchInformation();
+            listenerGamepad->SetTouchEvent(a.index(), a.touch_state());
+          }
+        }
+        break;
+      }
+      case GamepadChangeEventBody::TGamepadHandInformation: {
+        const GamepadHandInformation& a = body.get_GamepadHandInformation();
+        gamepad->SetHand(a.hand());
+        break;
+      }
+      default:
+        MOZ_ASSERT(false);
+        break;
+    }
+    ret = true;
+  }
+
+  if (aWindow && firstTime) {
+    FireConnectionEvent(aWindow, gamepad, true);
+  }
+
+  return ret;
+}
+
+already_AddRefed<Promise> GamepadManager::VibrateHaptic(
+    GamepadHandle aHandle, uint32_t aHapticIndex, double aIntensity,
+    double aDuration, nsIGlobalObject* aGlobal, ErrorResult& aRv) {
+  RefPtr<Promise> promise = Promise::Create(aGlobal, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return nullptr;
+  }
+  if (StaticPrefs::dom_gamepad_haptic_feedback_enabled()) {
+    if (aHandle.GetKind() == GamepadHandleKind::VR) {
+      if (gfx::VRManagerChild::IsCreated()) {
+        gfx::VRManagerChild* vm = gfx::VRManagerChild::Get();
+        vm->AddPromise(mPromiseID, promise);
+        vm->SendVibrateHaptic(aHandle, aHapticIndex, aIntensity, aDuration,
+                              mPromiseID);
+      }
+    } else {
+      if (mChannelChild) {
+        mChannelChild->AddPromise(mPromiseID, promise);
+        mChannelChild->SendVibrateHaptic(aHandle, aHapticIndex, aIntensity,
+                                         aDuration, mPromiseID);
+      }
+    }
+  }
+
+  ++mPromiseID;
+  return promise.forget();
+}
+
+void GamepadManager::StopHaptics() {
+  if (!StaticPrefs::dom_gamepad_haptic_feedback_enabled()) {
+    return;
+  }
+
+  for (const auto& entry : mGamepads) {
+    const GamepadHandle handle = entry.GetWeak()->GetHandle();
+    if (handle.GetKind() == GamepadHandleKind::VR) {
+      if (gfx::VRManagerChild::IsCreated()) {
+        gfx::VRManagerChild* vm = gfx::VRManagerChild::Get();
+        vm->SendStopVibrateHaptic(handle);
+      }
+    } else {
+      if (mChannelChild) {
+        mChannelChild->SendStopVibrateHaptic(handle);
+      }
+    }
+  }
+}
+
+already_AddRefed<Promise> GamepadManager::SetLightIndicatorColor(
+    GamepadHandle aHandle, uint32_t aLightColorIndex, uint8_t aRed,
+    uint8_t aGreen, uint8_t aBlue, nsIGlobalObject* aGlobal, ErrorResult& aRv) {
+  RefPtr<Promise> promise = Promise::Create(aGlobal, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return nullptr;
+  }
+  if (StaticPrefs::dom_gamepad_extensions_lightindicator()) {
+    MOZ_RELEASE_ASSERT(aHandle.GetKind() != GamepadHandleKind::VR,
+                       "We don't support light indicator in VR.");
+
+    if (mChannelChild) {
+      mChannelChild->AddPromise(mPromiseID, promise);
+      mChannelChild->SendLightIndicatorColor(aHandle, aLightColorIndex, aRed,
+                                             aGreen, aBlue, mPromiseID);
+    }
+  }
+
+  ++mPromiseID;
+  return promise.forget();
+}
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/GamepadManager.h b/dom/gamepad/GamepadManager.h
new file mode 100644
index 0000000000..794c0d1ca4
--- /dev/null
+++ b/dom/gamepad/GamepadManager.h
@@ -0,0 +1,156 @@
+/* -*- 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_GamepadManager_h_
+#define mozilla_dom_GamepadManager_h_
+
+#include "nsIObserver.h"
+#include "nsRefPtrHashtable.h"
+// Needed for GamepadMappingType
+#include "mozilla/dom/GamepadBinding.h"
+#include "mozilla/dom/GamepadHandle.h"
+#include <utility>
+
+class nsGlobalWindowInner;
+class nsIGlobalObject;
+
+namespace mozilla {
+namespace gfx {
+class VRManagerChild;
+}  // namespace gfx
+namespace dom {
+
+class EventTarget;
+class Gamepad;
+class GamepadChangeEvent;
+class GamepadEventChannelChild;
+
+class GamepadManager final : public nsIObserver {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+
+  // Returns true if we actually have a service up and running
+  static bool IsServiceRunning();
+  // Get the singleton service
+  static already_AddRefed<GamepadManager> GetService();
+
+  void BeginShutdown();
+  void StopMonitoring();
+
+  // Indicate that |aWindow| wants to receive gamepad events.
+  void AddListener(nsGlobalWindowInner* aWindow);
+  // Indicate that |aWindow| should no longer receive gamepad events.
+  void RemoveListener(nsGlobalWindowInner* aWindow);
+
+  // Add a gamepad to the list of known gamepads.
+  void AddGamepad(GamepadHandle aHandle, const nsAString& aID,
+                  GamepadMappingType aMapping, GamepadHand aHand,
+                  uint32_t aDisplayID, uint32_t aNumButtons, uint32_t aNumAxes,
+                  uint32_t aNumHaptics, uint32_t aNumLightIndicator,
+                  uint32_t aNumTouchEvents);
+
+  // Remove the gamepad at |aIndex| from the list of known gamepads.
+  void RemoveGamepad(GamepadHandle aHandle);
+
+  // Synchronize the state of |aGamepad| to match the gamepad stored at |aIndex|
+  void SyncGamepadState(GamepadHandle aHandle, nsGlobalWindowInner* aWindow,
+                        Gamepad* aGamepad);
+
+  // Returns gamepad object if index exists, null otherwise
+  already_AddRefed<Gamepad> GetGamepad(GamepadHandle aHandle) const;
+
+  // Receive GamepadChangeEvent messages from parent process to fire DOM events
+  void Update(const GamepadChangeEvent& aGamepadEvent);
+
+  // Trigger vibrate haptic event to gamepad channels.
+  already_AddRefed<Promise> VibrateHaptic(GamepadHandle aHandle,
+                                          uint32_t aHapticIndex,
+                                          double aIntensity, double aDuration,
+                                          nsIGlobalObject* aGlobal,
+                                          ErrorResult& aRv);
+  // Send stop haptic events to gamepad channels.
+  void StopHaptics();
+
+  // Set light indicator color event to gamepad channels.
+  already_AddRefed<Promise> SetLightIndicatorColor(GamepadHandle aHandle,
+                                                   uint32_t aLightColorIndex,
+                                                   uint8_t aRed, uint8_t aGreen,
+                                                   uint8_t aBlue,
+                                                   nsIGlobalObject* aGlobal,
+                                                   ErrorResult& aRv);
+
+ protected:
+  GamepadManager();
+  ~GamepadManager() = default;
+
+  // Fire a gamepadconnected or gamepaddisconnected event for the gamepad
+  // at |aIndex| to all windows that are listening and have received
+  // gamepad input.
+  void NewConnectionEvent(GamepadHandle aHandle, bool aConnected);
+
+  // Fire a gamepadaxismove event to the window at |aTarget| for |aGamepad|.
+  void FireAxisMoveEvent(EventTarget* aTarget, Gamepad* aGamepad, uint32_t axis,
+                         double value);
+
+  // Fire one of gamepadbutton{up,down} event at the window at |aTarget| for
+  // |aGamepad|.
+  void FireButtonEvent(EventTarget* aTarget, Gamepad* aGamepad,
+                       uint32_t aButton, double aValue);
+
+  // Fire one of gamepad{connected,disconnected} event at the window at
+  // |aTarget| for |aGamepad|.
+  void FireConnectionEvent(EventTarget* aTarget, Gamepad* aGamepad,
+                           bool aConnected);
+
+  // true if this feature is enabled in preferences
+  bool mEnabled;
+  // true if non-standard events are enabled in preferences
+  bool mNonstandardEventsEnabled;
+  // true when shutdown has begun
+  bool mShuttingDown;
+
+  RefPtr<GamepadEventChannelChild> mChannelChild;
+
+ private:
+  nsresult Init();
+
+  void MaybeConvertToNonstandardGamepadEvent(const GamepadChangeEvent& aEvent,
+                                             nsGlobalWindowInner* aWindow);
+
+  bool SetGamepadByEvent(const GamepadChangeEvent& aEvent,
+                         nsGlobalWindowInner* aWindow = nullptr);
+  // To avoid unintentionally causing the gamepad be activated.
+  // Returns false if this gamepad hasn't been seen by this window
+  // and the axis move data is less than AXIS_FIRST_INTENT_THRESHOLD_VALUE.
+  bool AxisMoveIsFirstIntent(nsGlobalWindowInner* aWindow,
+                             GamepadHandle aHandle,
+                             const GamepadChangeEvent& aEvent);
+  bool MaybeWindowHasSeenGamepad(nsGlobalWindowInner* aWindow,
+                                 GamepadHandle aHandle);
+  // Returns true if we have already sent data from this gamepad
+  // to this window. This should only return true if the user
+  // explicitly interacted with a gamepad while this window
+  // was focused, by pressing buttons or similar actions.
+  bool WindowHasSeenGamepad(nsGlobalWindowInner* aWindow,
+                            GamepadHandle aHandle) const;
+  // Indicate that a window has received data from a gamepad.
+  void SetWindowHasSeenGamepad(nsGlobalWindowInner* aWindow,
+                               GamepadHandle aHandle, bool aHasSeen = true);
+
+  // Gamepads connected to the system. Copies of these are handed out
+  // to each window.
+  nsRefPtrHashtable<nsGenericHashKey<GamepadHandle>, Gamepad> mGamepads;
+  // Inner windows that are listening for gamepad events.
+  // has been sent to that window.
+  nsTArray<RefPtr<nsGlobalWindowInner>> mListeners;
+  uint32_t mPromiseID;
+};
+
+}  // namespace dom
+}  // namespace mozilla
+
+#endif  // mozilla_dom_GamepadManager_h_
diff --git a/dom/gamepad/GamepadMonitoring.h b/dom/gamepad/GamepadMonitoring.h
new file mode 100644
index 0000000000..67b4737470
--- /dev/null
+++ b/dom/gamepad/GamepadMonitoring.h
@@ -0,0 +1,24 @@
+/* -*- 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_GamepadMonitoring_h_
+#define mozilla_dom_GamepadMonitoring_h_
+#include "mozilla/dom/GamepadHandle.h"
+
+namespace mozilla::dom {
+
+// These two functions are implemented in the platform specific service files
+// (linux/LinuxGamepad.cpp, cocoa/CocoaGamepad.cpp, etc)
+void StartGamepadMonitoring();
+void StopGamepadMonitoring();
+void SetGamepadLightIndicatorColor(const Tainted<GamepadHandle>& aGamepadHandle,
+                                   const Tainted<uint32_t>& aLightColorIndex,
+                                   const uint8_t& aRed, const uint8_t& aGreen,
+                                   const uint8_t& aBlue);
+
+}  // namespace mozilla::dom
+
+#endif
diff --git a/dom/gamepad/GamepadPlatformService.cpp b/dom/gamepad/GamepadPlatformService.cpp
new file mode 100644
index 0000000000..7d730e3d0a
--- /dev/null
+++ b/dom/gamepad/GamepadPlatformService.cpp
@@ -0,0 +1,336 @@
+/* -*- 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 "mozilla/dom/GamepadPlatformService.h"
+
+#include "mozilla/dom/GamepadEventChannelParent.h"
+#include "mozilla/dom/GamepadMonitoring.h"
+#include "mozilla/dom/GamepadTestChannelParent.h"
+#include "mozilla/ipc/BackgroundParent.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/Unused.h"
+
+#include "nsCOMPtr.h"
+#include "nsHashKeys.h"
+
+using namespace mozilla::ipc;
+
+namespace mozilla::dom {
+
+namespace {
+
+// This is the singleton instance of GamepadPlatformService, can be called
+// by both background and monitor thread.
+StaticRefPtr<GamepadPlatformService> gGamepadPlatformServiceSingleton;
+
+}  // namespace
+
+// static
+GamepadMonitoringState& GamepadMonitoringState::GetSingleton() {
+  static GamepadMonitoringState sInstance{};
+  return sInstance;
+}
+
+void GamepadMonitoringState::AddObserver(GamepadTestChannelParent* aParent) {
+  AssertIsOnBackgroundThread();
+  MOZ_ASSERT(aParent);
+  MOZ_ALWAYS_TRUE(mObservers.append(aParent));
+}
+
+void GamepadMonitoringState::RemoveObserver(GamepadTestChannelParent* aParent) {
+  AssertIsOnBackgroundThread();
+  MOZ_ASSERT(aParent);
+
+  WeakPtr<GamepadTestChannelParent>* observer = nullptr;
+
+  for (auto& item : mObservers) {
+    if (item == aParent) {
+      observer = &item;
+    }
+  }
+
+  MOZ_ASSERT(
+      observer,
+      "Attempted to remove a GamepadTestChannelParent that was never added");
+
+  std::swap(*observer, mObservers.back());
+  mObservers.popBack();
+}
+
+bool GamepadMonitoringState::IsMonitoring() const {
+  AssertIsOnBackgroundThread();
+  return mIsMonitoring;
+}
+
+void GamepadMonitoringState::Set(bool aIsMonitoring) {
+  AssertIsOnBackgroundThread();
+
+  if (mIsMonitoring != aIsMonitoring) {
+    mIsMonitoring = aIsMonitoring;
+    for (auto& observer : mObservers) {
+      // Since each GamepadTestChannelParent removes itself in its dtor, this
+      // should never be nullptr
+      MOZ_RELEASE_ASSERT(observer);
+      observer->OnMonitoringStateChanged(aIsMonitoring);
+    }
+  }
+}
+
+GamepadPlatformService::GamepadPlatformService()
+    : mNextGamepadHandleValue(1),
+      mMutex("mozilla::dom::GamepadPlatformService") {}
+
+GamepadPlatformService::~GamepadPlatformService() { Cleanup(); }
+
+// static
+already_AddRefed<GamepadPlatformService>
+GamepadPlatformService::GetParentService() {
+  // GamepadPlatformService can only be accessed in parent process
+  MOZ_ASSERT(XRE_IsParentProcess());
+  if (!gGamepadPlatformServiceSingleton) {
+    // Only Background Thread can create new GamepadPlatformService instance.
+    if (IsOnBackgroundThread()) {
+      gGamepadPlatformServiceSingleton = new GamepadPlatformService();
+    } else {
+      return nullptr;
+    }
+  }
+  RefPtr<GamepadPlatformService> service(gGamepadPlatformServiceSingleton);
+  return service.forget();
+}
+
+template <class T>
+void GamepadPlatformService::NotifyGamepadChange(GamepadHandle aHandle,
+                                                 const T& aInfo) {
+  // This method is called by monitor populated in
+  // platform-dependent backends
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(!NS_IsMainThread());
+
+  GamepadChangeEventBody body(aInfo);
+  GamepadChangeEvent e(aHandle, body);
+
+  // mChannelParents may be accessed by background thread in the
+  // same time, we use mutex to prevent possible race condtion
+  MutexAutoLock autoLock(mMutex);
+
+  for (uint32_t i = 0; i < mChannelParents.Length(); ++i) {
+    mChannelParents[i]->DispatchUpdateEvent(e);
+  }
+}
+
+GamepadHandle GamepadPlatformService::AddGamepad(
+    const char* aID, GamepadMappingType aMapping, GamepadHand aHand,
+    uint32_t aNumButtons, uint32_t aNumAxes, uint32_t aHaptics,
+    uint32_t aNumLightIndicator, uint32_t aNumTouchEvents) {
+  // This method is called by monitor thread populated in
+  // platform-dependent backends
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(!NS_IsMainThread());
+
+  GamepadHandle gamepadHandle{mNextGamepadHandleValue++,
+                              GamepadHandleKind::GamepadPlatformManager};
+
+  // Only VR controllers has displayID, we give 0 to the general gamepads.
+  GamepadAdded a(NS_ConvertUTF8toUTF16(nsDependentCString(aID)), aMapping,
+                 aHand, 0, aNumButtons, aNumAxes, aHaptics, aNumLightIndicator,
+                 aNumTouchEvents);
+
+  mGamepadAdded.emplace(gamepadHandle, a);
+  NotifyGamepadChange<GamepadAdded>(gamepadHandle, a);
+  return gamepadHandle;
+}
+
+void GamepadPlatformService::RemoveGamepad(GamepadHandle aHandle) {
+  // This method is called by monitor thread populated in
+  // platform-dependent backends
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(!NS_IsMainThread());
+  GamepadRemoved a;
+  NotifyGamepadChange<GamepadRemoved>(aHandle, a);
+  mGamepadAdded.erase(aHandle);
+}
+
+void GamepadPlatformService::NewButtonEvent(GamepadHandle aHandle,
+                                            uint32_t aButton, bool aPressed,
+                                            bool aTouched, double aValue) {
+  // This method is called by monitor thread populated in
+  // platform-dependent backends
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(!NS_IsMainThread());
+  GamepadButtonInformation a(aButton, aValue, aPressed, aTouched);
+  NotifyGamepadChange<GamepadButtonInformation>(aHandle, a);
+}
+
+void GamepadPlatformService::NewButtonEvent(GamepadHandle aHandle,
+                                            uint32_t aButton, bool aPressed,
+                                            double aValue) {
+  // This method is called by monitor thread populated in
+  // platform-dependent backends
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(!NS_IsMainThread());
+  // When only a digital button is available the value will be synthesized.
+  NewButtonEvent(aHandle, aButton, aPressed, aPressed, aValue);
+}
+
+void GamepadPlatformService::NewButtonEvent(GamepadHandle aHandle,
+                                            uint32_t aButton, bool aPressed,
+                                            bool aTouched) {
+  // This method is called by monitor thread populated in
+  // platform-dependent backends
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(!NS_IsMainThread());
+  // When only a digital button is available the value will be synthesized.
+  NewButtonEvent(aHandle, aButton, aPressed, aTouched, aPressed ? 1.0L : 0.0L);
+}
+
+void GamepadPlatformService::NewButtonEvent(GamepadHandle aHandle,
+                                            uint32_t aButton, bool aPressed) {
+  // This method is called by monitor thread populated in
+  // platform-dependent backends
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(!NS_IsMainThread());
+  // When only a digital button is available the value will be synthesized.
+  NewButtonEvent(aHandle, aButton, aPressed, aPressed, aPressed ? 1.0L : 0.0L);
+}
+
+void GamepadPlatformService::NewAxisMoveEvent(GamepadHandle aHandle,
+                                              uint32_t aAxis, double aValue) {
+  // This method is called by monitor thread populated in
+  // platform-dependent backends
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(!NS_IsMainThread());
+  GamepadAxisInformation a(aAxis, aValue);
+  NotifyGamepadChange<GamepadAxisInformation>(aHandle, a);
+}
+
+void GamepadPlatformService::NewLightIndicatorTypeEvent(
+    GamepadHandle aHandle, uint32_t aLight, GamepadLightIndicatorType aType) {
+  // This method is called by monitor thread populated in
+  // platform-dependent backends
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(!NS_IsMainThread());
+  GamepadLightIndicatorTypeInformation a(aLight, aType);
+  NotifyGamepadChange<GamepadLightIndicatorTypeInformation>(aHandle, a);
+}
+
+void GamepadPlatformService::NewPoseEvent(GamepadHandle aHandle,
+                                          const GamepadPoseState& aState) {
+  // This method is called by monitor thread populated in
+  // platform-dependent backends
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(!NS_IsMainThread());
+  GamepadPoseInformation a(aState);
+  NotifyGamepadChange<GamepadPoseInformation>(aHandle, a);
+}
+
+void GamepadPlatformService::NewMultiTouchEvent(
+    GamepadHandle aHandle, uint32_t aTouchArrayIndex,
+    const GamepadTouchState& aState) {
+  // This method is called by monitor thread populated in
+  // platform-dependent backends
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(!NS_IsMainThread());
+
+  GamepadTouchInformation a(aTouchArrayIndex, aState);
+  NotifyGamepadChange<GamepadTouchInformation>(aHandle, a);
+}
+
+void GamepadPlatformService::ResetGamepadIndexes() {
+  // This method is called by monitor thread populated in
+  // platform-dependent backends
+  MOZ_ASSERT(XRE_IsParentProcess());
+  MOZ_ASSERT(!NS_IsMainThread());
+  mNextGamepadHandleValue = 1;
+}
+
+void GamepadPlatformService::AddChannelParent(
+    GamepadEventChannelParent* aParent) {
+  // mChannelParents can only be modified once GamepadEventChannelParent
+  // is created or removed in Background thread
+  AssertIsOnBackgroundThread();
+  MOZ_ASSERT(aParent);
+  MOZ_ASSERT(!mChannelParents.Contains(aParent));
+
+  // We use mutex here to prevent race condition with monitor thread
+  {
+    MutexAutoLock autoLock(mMutex);
+    mChannelParents.AppendElement(aParent);
+
+    // For a new GamepadEventChannel, we have to send the exising GamepadAdded
+    // to it to make it can have the same amount of gamepads with others.
+    if (mChannelParents.Length() > 1) {
+      for (const auto& evt : mGamepadAdded) {
+        GamepadChangeEventBody body(evt.second);
+        GamepadChangeEvent e(evt.first, body);
+        aParent->DispatchUpdateEvent(e);
+      }
+    }
+  }
+
+  StartGamepadMonitoring();
+
+  GamepadMonitoringState::GetSingleton().Set(true);
+}
+
+void GamepadPlatformService::RemoveChannelParent(
+    GamepadEventChannelParent* aParent) {
+  // mChannelParents can only be modified once GamepadEventChannelParent
+  // is created or removed in Background thread
+  AssertIsOnBackgroundThread();
+  MOZ_ASSERT(aParent);
+  MOZ_ASSERT(mChannelParents.Contains(aParent));
+
+  // We use mutex here to prevent race condition with monitor thread
+  {
+    MutexAutoLock autoLock(mMutex);
+    mChannelParents.RemoveElement(aParent);
+    if (!mChannelParents.IsEmpty()) {
+      return;
+    }
+  }
+
+  GamepadMonitoringState::GetSingleton().Set(false);
+
+  StopGamepadMonitoring();
+  ResetGamepadIndexes();
+  MaybeShutdown();
+}
+
+void GamepadPlatformService::MaybeShutdown() {
+  // This method is invoked in MaybeStopGamepadMonitoring when
+  // an IPDL channel is going to be destroyed
+  AssertIsOnBackgroundThread();
+
+  // We have to release gGamepadPlatformServiceSingleton ouside
+  // the mutex as well as making upcoming GetParentService() call
+  // recreate new singleton, so we use this RefPtr to temporarily
+  // hold the reference, postponing the release process until this
+  // method ends.
+  RefPtr<GamepadPlatformService> kungFuDeathGrip;
+
+  bool isChannelParentEmpty;
+  {
+    MutexAutoLock autoLock(mMutex);
+    isChannelParentEmpty = mChannelParents.IsEmpty();
+    if (isChannelParentEmpty) {
+      kungFuDeathGrip = gGamepadPlatformServiceSingleton;
+      gGamepadPlatformServiceSingleton = nullptr;
+      mGamepadAdded.clear();
+    }
+  }
+}
+
+void GamepadPlatformService::Cleanup() {
+  // This method is called when GamepadPlatformService is
+  // successfully distructed in background thread
+  AssertIsOnBackgroundThread();
+
+  MutexAutoLock autoLock(mMutex);
+  mChannelParents.Clear();
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/GamepadPlatformService.h b/dom/gamepad/GamepadPlatformService.h
new file mode 100644
index 0000000000..7353f1f449
--- /dev/null
+++ b/dom/gamepad/GamepadPlatformService.h
@@ -0,0 +1,150 @@
+/* -*- 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_GamepadPlatformService_h_
+#define mozilla_dom_GamepadPlatformService_h_
+
+#include "mozilla/dom/GamepadBinding.h"
+#include "mozilla/dom/GamepadHandle.h"
+
+#include <map>
+#include "mozilla/Mutex.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/Vector.h"
+#include "mozilla/WeakPtr.h"
+
+namespace mozilla::dom {
+
+class GamepadAdded;
+class GamepadEventChannelParent;
+enum class GamepadLightIndicatorType : uint8_t;
+struct GamepadPoseState;
+class GamepadTestChannelParent;
+struct GamepadTouchState;
+class GamepadPlatformService;
+
+class GamepadMonitoringState {
+ public:
+  static GamepadMonitoringState& GetSingleton();
+
+  void AddObserver(GamepadTestChannelParent* aParent);
+  void RemoveObserver(GamepadTestChannelParent* aParent);
+
+  bool IsMonitoring() const;
+
+  GamepadMonitoringState(const GamepadMonitoringState&) = delete;
+  GamepadMonitoringState(GamepadMonitoringState&&) = delete;
+  GamepadMonitoringState& operator=(const GamepadMonitoringState) = delete;
+  GamepadMonitoringState& operator=(GamepadMonitoringState&&) = delete;
+
+ private:
+  GamepadMonitoringState() = default;
+  ~GamepadMonitoringState() = default;
+
+  void Set(bool aIsMonitoring);
+
+  bool mIsMonitoring{false};
+  Vector<WeakPtr<GamepadTestChannelParent>> mObservers;
+
+  friend class mozilla::dom::GamepadPlatformService;
+};
+
+// Platform Service for building and transmitting IPDL messages
+// through the HAL sandbox. Used by platform specific
+// Gamepad implementations
+//
+// This class can be accessed by the following 2 threads :
+// 1. Background thread:
+//    This thread takes charge of IPDL communications
+//    between here and DOM side
+//
+// 2. Monitor Thread:
+//    This thread is populated in platform-dependent backends, which
+//    is in charge of processing gamepad hardware events from OS
+class GamepadPlatformService final {
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(GamepadPlatformService)
+ public:
+  // Get the singleton service
+  static already_AddRefed<GamepadPlatformService> GetParentService();
+
+  // Add a gamepad to the list of known gamepads, and return its handle.
+  GamepadHandle AddGamepad(const char* aID, GamepadMappingType aMapping,
+                           GamepadHand aHand, uint32_t aNumButtons,
+                           uint32_t aNumAxes, uint32_t aNumHaptics,
+                           uint32_t aNumLightIndicator,
+                           uint32_t aNumTouchEvents);
+  // Remove the gamepad at |aHandle| from the list of known gamepads.
+  void RemoveGamepad(GamepadHandle aHandle);
+
+  // Update the state of |aButton| for the gamepad at |aHandle| for all
+  // windows that are listening and visible, and fire one of
+  // a gamepadbutton{up,down} event at them as well.
+  // aPressed is used for digital buttons, aTouched is for detecting touched
+  // events, aValue is for analog buttons.
+  void NewButtonEvent(GamepadHandle aHandle, uint32_t aButton, bool aPressed,
+                      bool aTouched, double aValue);
+  // When only a digital button is available the value will be synthesized.
+  void NewButtonEvent(GamepadHandle aHandle, uint32_t aButton, bool aPressed);
+  // When only a digital button are available the value will be synthesized.
+  void NewButtonEvent(GamepadHandle aHandle, uint32_t aButton, bool aPressed,
+                      bool aTouched);
+  // When only a digital button are available the value will be synthesized.
+  void NewButtonEvent(GamepadHandle aHandle, uint32_t aButton, bool aPressed,
+                      double aValue);
+  // Update the state of |aAxis| for the gamepad at |aHandle| for all
+  // windows that are listening and visible, and fire a gamepadaxismove
+  // event at them as well.
+  void NewAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis, double aValue);
+  // Update the state of |aState| for the gamepad at |aHandle| for all
+  // windows that are listening and visible.
+  void NewPoseEvent(GamepadHandle aHandle, const GamepadPoseState& aState);
+  // Update the type of |aType| for the gamepad at |aHandle| for all
+  // windows that are listening and visible.
+  void NewLightIndicatorTypeEvent(GamepadHandle aHandle, uint32_t aLight,
+                                  GamepadLightIndicatorType aType);
+  // Update the state of |aState| for the gamepad at |aHandle| with
+  // |aTouchArrayIndex| for all windows that are listening and visible.
+  void NewMultiTouchEvent(GamepadHandle aHandle, uint32_t aTouchArrayIndex,
+                          const GamepadTouchState& aState);
+
+  // When shutting down the platform communications for gamepad, also reset the
+  // indexes.
+  void ResetGamepadIndexes();
+
+  // Add IPDL parent instance
+  void AddChannelParent(GamepadEventChannelParent* aParent);
+
+  // Remove IPDL parent instance
+  void RemoveChannelParent(GamepadEventChannelParent* aParent);
+
+  void MaybeShutdown();
+
+ private:
+  GamepadPlatformService();
+  ~GamepadPlatformService();
+  template <class T>
+  void NotifyGamepadChange(GamepadHandle aHandle, const T& aInfo);
+
+  void Cleanup();
+
+  // mNextGamepadHandleValue can only be accessed by monitor thread
+  uint32_t mNextGamepadHandleValue;
+
+  // mChannelParents stores all the GamepadEventChannelParent instances
+  // which may be accessed by both background thread and monitor thread
+  // simultaneously, so we have a mutex to prevent race condition
+  nsTArray<RefPtr<GamepadEventChannelParent>> mChannelParents;
+
+  // This mutex protects mChannelParents from race condition
+  // between background and monitor thread
+  Mutex mMutex MOZ_UNANNOTATED;
+
+  std::map<GamepadHandle, GamepadAdded> mGamepadAdded;
+};
+
+}  // namespace mozilla::dom
+
+#endif
diff --git a/dom/gamepad/GamepadPose.cpp b/dom/gamepad/GamepadPose.cpp
new file mode 100644
index 0000000000..e2a5d09efc
--- /dev/null
+++ b/dom/gamepad/GamepadPose.cpp
@@ -0,0 +1,110 @@
+/* -*- 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 "nsWrapperCache.h"
+
+#include "mozilla/HoldDropJSObjects.h"
+#include "mozilla/dom/GamepadPoseBinding.h"
+#include "mozilla/dom/GamepadPose.h"
+
+namespace mozilla::dom {
+
+GamepadPose::GamepadPose(nsISupports* aParent, const GamepadPoseState& aState)
+    : Pose(aParent), mPoseState(aState) {
+  mozilla::HoldJSObjects(this);
+}
+
+GamepadPose::GamepadPose(nsISupports* aParent) : Pose(aParent) {
+  mozilla::HoldJSObjects(this);
+  mPoseState.Clear();
+}
+
+GamepadPose::~GamepadPose() { mozilla::DropJSObjects(this); }
+
+/* virtual */
+JSObject* GamepadPose::WrapObject(JSContext* aJSContext,
+                                  JS::Handle<JSObject*> aGivenProto) {
+  return GamepadPose_Binding::Wrap(aJSContext, this, aGivenProto);
+}
+
+bool GamepadPose::HasOrientation() const {
+  return bool(mPoseState.flags & GamepadCapabilityFlags::Cap_Orientation);
+}
+
+bool GamepadPose::HasPosition() const {
+  return bool(mPoseState.flags & GamepadCapabilityFlags::Cap_Position) ||
+         bool(mPoseState.flags & GamepadCapabilityFlags::Cap_PositionEmulated);
+}
+
+void GamepadPose::GetPosition(JSContext* aJSContext,
+                              JS::MutableHandle<JSObject*> aRetval,
+                              ErrorResult& aRv) {
+  const bool valid =
+      mPoseState.isPositionValid &&
+      (bool(mPoseState.flags & GamepadCapabilityFlags::Cap_Position) ||
+       bool(mPoseState.flags & GamepadCapabilityFlags::Cap_PositionEmulated));
+  SetFloat32Array(aJSContext, this, aRetval, mPosition,
+                  valid ? mPoseState.position : nullptr, 3, aRv);
+}
+
+void GamepadPose::GetLinearVelocity(JSContext* aJSContext,
+                                    JS::MutableHandle<JSObject*> aRetval,
+                                    ErrorResult& aRv) {
+  const bool valid =
+      mPoseState.isPositionValid &&
+      (bool(mPoseState.flags & GamepadCapabilityFlags::Cap_Position) ||
+       bool(mPoseState.flags & GamepadCapabilityFlags::Cap_PositionEmulated));
+  SetFloat32Array(aJSContext, this, aRetval, mLinearVelocity,
+                  valid ? mPoseState.linearVelocity : nullptr, 3, aRv);
+}
+
+void GamepadPose::GetLinearAcceleration(JSContext* aJSContext,
+                                        JS::MutableHandle<JSObject*> aRetval,
+                                        ErrorResult& aRv) {
+  const bool valid =
+      mPoseState.isPositionValid &&
+      bool(mPoseState.flags & GamepadCapabilityFlags::Cap_LinearAcceleration);
+  SetFloat32Array(aJSContext, this, aRetval, mLinearAcceleration,
+                  valid ? mPoseState.linearAcceleration : nullptr, 3, aRv);
+}
+
+void GamepadPose::GetOrientation(JSContext* aJSContext,
+                                 JS::MutableHandle<JSObject*> aRetval,
+                                 ErrorResult& aRv) {
+  const bool valid =
+      mPoseState.isOrientationValid &&
+      bool(mPoseState.flags & GamepadCapabilityFlags::Cap_Orientation);
+  SetFloat32Array(aJSContext, this, aRetval, mOrientation,
+                  valid ? mPoseState.orientation : nullptr, 4, aRv);
+}
+
+void GamepadPose::GetAngularVelocity(JSContext* aJSContext,
+                                     JS::MutableHandle<JSObject*> aRetval,
+                                     ErrorResult& aRv) {
+  const bool valid =
+      mPoseState.isOrientationValid &&
+      bool(mPoseState.flags & GamepadCapabilityFlags::Cap_Orientation);
+  SetFloat32Array(aJSContext, this, aRetval, mAngularVelocity,
+                  valid ? mPoseState.angularVelocity : nullptr, 3, aRv);
+}
+
+void GamepadPose::GetAngularAcceleration(JSContext* aJSContext,
+                                         JS::MutableHandle<JSObject*> aRetval,
+                                         ErrorResult& aRv) {
+  const bool valid =
+      mPoseState.isOrientationValid &&
+      bool(mPoseState.flags & GamepadCapabilityFlags::Cap_AngularAcceleration);
+  SetFloat32Array(aJSContext, this, aRetval, mAngularAcceleration,
+                  valid ? mPoseState.angularAcceleration : nullptr, 3, aRv);
+}
+
+void GamepadPose::SetPoseState(const GamepadPoseState& aPose) {
+  mPoseState = aPose;
+}
+
+const GamepadPoseState& GamepadPose::GetPoseState() { return mPoseState; }
+
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/GamepadPose.h b/dom/gamepad/GamepadPose.h
new file mode 100644
index 0000000000..2dabfa1117
--- /dev/null
+++ b/dom/gamepad/GamepadPose.h
@@ -0,0 +1,57 @@
+/* -*- 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_gamepad_GamepadPose_h
+#define mozilla_dom_gamepad_GamepadPose_h
+
+#include "mozilla/TypedEnumBits.h"
+#include "mozilla/dom/Pose.h"
+#include "mozilla/dom/GamepadPoseState.h"
+#include "nsCOMPtr.h"
+
+namespace mozilla::dom {
+
+class GamepadPose final : public Pose {
+ public:
+  GamepadPose(nsISupports* aParent, const GamepadPoseState& aState);
+  explicit GamepadPose(nsISupports* aParent);
+
+  virtual JSObject* WrapObject(JSContext* aCx,
+                               JS::Handle<JSObject*> aGivenProto) override;
+
+  bool HasOrientation() const;
+  bool HasPosition() const;
+  virtual void GetPosition(JSContext* aJSContext,
+                           JS::MutableHandle<JSObject*> aRetval,
+                           ErrorResult& aRv) override;
+  virtual void GetLinearVelocity(JSContext* aJSContext,
+                                 JS::MutableHandle<JSObject*> aRetval,
+                                 ErrorResult& aRv) override;
+  virtual void GetLinearAcceleration(JSContext* aJSContext,
+                                     JS::MutableHandle<JSObject*> aRetval,
+                                     ErrorResult& aRv) override;
+  virtual void GetOrientation(JSContext* aJSContext,
+                              JS::MutableHandle<JSObject*> aRetval,
+                              ErrorResult& aRv) override;
+  virtual void GetAngularVelocity(JSContext* aJSContext,
+                                  JS::MutableHandle<JSObject*> aRetval,
+                                  ErrorResult& aRv) override;
+  virtual void GetAngularAcceleration(JSContext* aJSContext,
+                                      JS::MutableHandle<JSObject*> aRetval,
+                                      ErrorResult& aRv) override;
+  void SetPoseState(const GamepadPoseState& aPose);
+  const GamepadPoseState& GetPoseState();
+
+ private:
+  virtual ~GamepadPose();
+
+  nsCOMPtr<nsISupports> mParent;
+  GamepadPoseState mPoseState;
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_gamepad_GamepadPose_h
diff --git a/dom/gamepad/GamepadPoseState.h b/dom/gamepad/GamepadPoseState.h
new file mode 100644
index 0000000000..2272b84c76
--- /dev/null
+++ b/dom/gamepad/GamepadPoseState.h
@@ -0,0 +1,110 @@
+/* -*- 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_gamepad_GamepadPoseState_h_
+#define mozilla_dom_gamepad_GamepadPoseState_h_
+
+namespace mozilla::dom {
+
+enum class GamepadCapabilityFlags : uint16_t {
+  Cap_None = 0,
+  /**
+   * Cap_Position is set if the Gamepad is capable of tracking its position.
+   */
+  Cap_Position = 1 << 1,
+  /**
+   * Cap_Orientation is set if the Gamepad is capable of tracking its
+   * orientation.
+   */
+  Cap_Orientation = 1 << 2,
+  /**
+   * Cap_AngularAcceleration is set if the Gamepad is capable of tracking its
+   * angular acceleration.
+   */
+  Cap_AngularAcceleration = 1 << 3,
+  /**
+   * Cap_LinearAcceleration is set if the Gamepad is capable of tracking its
+   * linear acceleration.
+   */
+  Cap_LinearAcceleration = 1 << 4,
+  /**
+   * Cap_GripSpacePosition is set if the Gamepad has a grip space position.
+   */
+  Cap_GripSpacePosition = 1 << 5,
+  /**
+   * Cap_PositionEmulated is set if the VRDisplay is capable of setting a
+   * emulated position (e.g. neck model) even if still doesn't support 6DOF
+   * tracking.
+   */
+  Cap_PositionEmulated = 1 << 6,
+  /**
+   * Cap_All used for validity checking during IPC serialization
+   */
+  Cap_All = (1 << 7) - 1
+};
+
+MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(GamepadCapabilityFlags)
+
+struct GamepadPoseState {
+  GamepadCapabilityFlags flags;
+  float orientation[4];
+  float position[3];
+  float angularVelocity[3];
+  float angularAcceleration[3];
+  float linearVelocity[3];
+  float linearAcceleration[3];
+  bool isPositionValid;
+  bool isOrientationValid;
+
+  GamepadPoseState()
+      : flags(GamepadCapabilityFlags::Cap_None),
+        orientation{0, 0, 0, 0},
+        position{0, 0, 0},
+        angularVelocity{0, 0, 0},
+        angularAcceleration{0, 0, 0},
+        linearVelocity{0, 0, 0},
+        linearAcceleration{0, 0, 0},
+        isPositionValid(false),
+        isOrientationValid(false) {}
+
+  bool operator==(const GamepadPoseState& aPose) const {
+    return flags == aPose.flags && orientation[0] == aPose.orientation[0] &&
+           orientation[1] == aPose.orientation[1] &&
+           orientation[2] == aPose.orientation[2] &&
+           orientation[3] == aPose.orientation[3] &&
+           position[0] == aPose.position[0] &&
+           position[1] == aPose.position[1] &&
+           position[2] == aPose.position[2] &&
+           angularVelocity[0] == aPose.angularVelocity[0] &&
+           angularVelocity[1] == aPose.angularVelocity[1] &&
+           angularVelocity[2] == aPose.angularVelocity[2] &&
+           angularAcceleration[0] == aPose.angularAcceleration[0] &&
+           angularAcceleration[1] == aPose.angularAcceleration[1] &&
+           angularAcceleration[2] == aPose.angularAcceleration[2] &&
+           linearVelocity[0] == aPose.linearVelocity[0] &&
+           linearVelocity[1] == aPose.linearVelocity[1] &&
+           linearVelocity[2] == aPose.linearVelocity[2] &&
+           linearAcceleration[0] == aPose.linearAcceleration[0] &&
+           linearAcceleration[1] == aPose.linearAcceleration[1] &&
+           linearAcceleration[2] == aPose.linearAcceleration[2] &&
+           isPositionValid == aPose.isPositionValid &&
+           isOrientationValid == aPose.isOrientationValid;
+  }
+
+  bool operator!=(const GamepadPoseState& aPose) const {
+    return !(*this == aPose);
+  }
+
+  void Clear() {
+    memset(&flags, 0,
+           reinterpret_cast<char*>(&isOrientationValid) +
+               sizeof(isOrientationValid) - reinterpret_cast<char*>(&flags));
+  }
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_gamepad_GamepadPoseState_h_
diff --git a/dom/gamepad/GamepadRemapping.cpp b/dom/gamepad/GamepadRemapping.cpp
new file mode 100644
index 0000000000..2c3ec252f5
--- /dev/null
+++ b/dom/gamepad/GamepadRemapping.cpp
@@ -0,0 +1,2178 @@
+/* -*- 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/. */
+
+// Based on
+// https://cs.chromium.org/chromium/src/device/gamepad/gamepad_standard_mappings.h
+
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "mozilla/dom/GamepadRemapping.h"
+#include "mozilla/dom/GamepadPlatformService.h"
+
+#include <vector>
+#include <unordered_map>
+
+namespace mozilla::dom {
+
+const float BUTTON_THRESHOLD_VALUE = 0.1f;
+
+float NormalizeTouch(long aValue, long aMin, long aMax) {
+  return (2.f * (aValue - aMin) / static_cast<float>(aMax - aMin)) - 1.f;
+}
+
+double AxisToButtonValue(double aValue) {
+  // Mapping axis value range from (-1, +1) to (0, +1).
+  return (aValue + 1.0f) * 0.5f;
+}
+
+void FetchDpadFromAxis(GamepadHandle aHandle, double dir) {
+  bool up = false;
+  bool right = false;
+  bool down = false;
+  bool left = false;
+
+  // Dpad is mapped as a direction on one axis, where -1 is up and it
+  // increases clockwise to 1, which is up + left. It's set to a large (> 1.f)
+  // number when nothing is depressed, except on start up, sometimes it's 0.0
+  // for no data, rather than the large number.
+  if (dir != 0.0f) {
+    up = (dir >= -1.f && dir < -0.7f) || (dir >= .95f && dir <= 1.f);
+    right = dir >= -.75f && dir < -.1f;
+    down = dir >= -.2f && dir < .45f;
+    left = dir >= .4f && dir <= 1.f;
+  }
+
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  if (!service) {
+    return;
+  }
+
+  service->NewButtonEvent(aHandle, BUTTON_INDEX_DPAD_UP, up);
+  service->NewButtonEvent(aHandle, BUTTON_INDEX_DPAD_RIGHT, right);
+  service->NewButtonEvent(aHandle, BUTTON_INDEX_DPAD_DOWN, down);
+  service->NewButtonEvent(aHandle, BUTTON_INDEX_DPAD_LEFT, left);
+}
+
+class DefaultRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return numAxes; }
+
+  virtual uint32_t GetButtonCount() const override { return numButtons; }
+
+  virtual void SetAxisCount(uint32_t aAxisCount) override {
+    numAxes = aAxisCount;
+  }
+
+  virtual void SetButtonCount(uint32_t aButtonCount) override {
+    numButtons = aButtonCount;
+  }
+
+  virtual GamepadMappingType GetMappingType() const override {
+    return GamepadMappingType::_empty;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    if (GetAxisCount() <= aAxis) {
+      NS_WARNING(
+          nsPrintfCString("Axis idx '%d' doesn't support in DefaultRemapper().",
+                          aAxis)
+              .get());
+      return;
+    }
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+    service->NewAxisMoveEvent(aHandle, aAxis, aValue);
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in DefaultRemapper().", aButton)
+              .get());
+      return;
+    }
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+    service->NewButtonEvent(aHandle, aButton, aPressed);
+  }
+
+ private:
+  uint32_t numAxes;
+  uint32_t numButtons;
+};
+
+class ADT1Remapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return BUTTON_INDEX_COUNT;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 3: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 4: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 5:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 9:
+        FetchDpadFromAxis(aHandle, aValue);
+        break;
+      default:
+        NS_WARNING(
+            nsPrintfCString("Axis idx '%d' doesn't support in ADT1Remapper().",
+                            aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString("Button idx '%d' doesn't support in ADT1Remapper().",
+                          aButton)
+              .get());
+      return;
+    }
+
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {3, BUTTON_INDEX_TERTIARY},
+        {4, BUTTON_INDEX_QUATERNARY},
+        {6, BUTTON_INDEX_LEFT_SHOULDER},
+        {7, BUTTON_INDEX_RIGHT_SHOULDER},
+        {12, BUTTON_INDEX_META},
+        {13, BUTTON_INDEX_LEFT_THUMBSTICK},
+        {14, BUTTON_INDEX_RIGHT_THUMBSTICK}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+};
+
+class TwoAxesEightKeysRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return 0; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return BUTTON_INDEX_COUNT - 1;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_DPAD_LEFT,
+                                AxisNegativeAsButton(aValue));
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_DPAD_RIGHT,
+                                AxisPositiveAsButton(aValue));
+        break;
+      case 1:
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_DPAD_UP,
+                                AxisNegativeAsButton(aValue));
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_DPAD_DOWN,
+                                AxisPositiveAsButton(aValue));
+        break;
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in TwoAxesEightKeysRemapper().",
+                aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in TwoAxesEightKeysRemapper().",
+              aButton)
+              .get());
+      return;
+    }
+
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {0, BUTTON_INDEX_QUATERNARY},
+        {2, BUTTON_INDEX_PRIMARY},
+        {3, BUTTON_INDEX_TERTIARY}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+};
+
+class StadiaControllerRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return STADIA_BUTTON_COUNT;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 3:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 4: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 5: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in StadiaControllerRemapper().",
+                aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (STADIA_BUTTON_COUNT <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in StadiaControllerRemapper().",
+              aButton)
+              .get());
+      return;
+    }
+
+    service->NewButtonEvent(aHandle, aButton, aPressed);
+  }
+
+ private:
+  enum STADIAButtons {
+    STADIA_BUTTON_EXTRA1 = BUTTON_INDEX_COUNT,
+    STADIA_BUTTON_EXTRA2,
+    STADIA_BUTTON_COUNT
+  };
+};
+
+class Playstation3Remapper final : public GamepadRemapper {
+ public:
+  Playstation3Remapper() = default;
+
+  uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  uint32_t GetButtonCount() const override { return BUTTON_INDEX_COUNT; }
+
+  void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                          double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 5:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in Playstation3Remapper().",
+                aAxis)
+                .get());
+        break;
+    }
+  }
+
+  void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                        bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    constexpr std::array buttonMapping = {BUTTON_INDEX_BACK_SELECT,
+                                          BUTTON_INDEX_LEFT_THUMBSTICK,
+                                          BUTTON_INDEX_RIGHT_THUMBSTICK,
+                                          BUTTON_INDEX_START,
+                                          BUTTON_INDEX_DPAD_UP,
+                                          BUTTON_INDEX_DPAD_RIGHT,
+                                          BUTTON_INDEX_DPAD_DOWN,
+                                          BUTTON_INDEX_DPAD_LEFT,
+                                          BUTTON_INDEX_LEFT_TRIGGER,
+                                          BUTTON_INDEX_RIGHT_TRIGGER,
+                                          BUTTON_INDEX_LEFT_SHOULDER,
+                                          BUTTON_INDEX_RIGHT_SHOULDER,
+                                          BUTTON_INDEX_QUATERNARY,
+                                          BUTTON_INDEX_SECONDARY,
+                                          BUTTON_INDEX_PRIMARY,
+                                          BUTTON_INDEX_TERTIARY,
+                                          BUTTON_INDEX_META};
+
+    if (buttonMapping.size() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in Playstation3Remapper().",
+              aButton)
+              .get());
+      return;
+    }
+    service->NewButtonEvent(aHandle, buttonMapping[aButton], aPressed);
+  }
+};
+
+class Dualshock4Remapper final : public GamepadRemapper {
+ public:
+  Dualshock4Remapper() {
+    mLastTouches.SetLength(TOUCH_EVENT_COUNT);
+    mLastTouchId.SetLength(TOUCH_EVENT_COUNT);
+  }
+
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return DUALSHOCK_BUTTON_COUNT;
+  }
+
+  virtual uint32_t GetLightIndicatorCount() const override {
+    return LIGHT_INDICATOR_COUNT;
+  }
+
+  virtual void GetLightIndicators(
+      nsTArray<GamepadLightIndicatorType>& aTypes) const override {
+    const uint32_t len = GetLightIndicatorCount();
+    aTypes.SetLength(len);
+    for (uint32_t i = 0; i < len; ++i) {
+      aTypes[i] = GamepadLightIndicatorType::Rgb;
+    }
+  }
+
+  virtual uint32_t GetTouchEventCount() const override {
+    return TOUCH_EVENT_COUNT;
+  }
+
+  virtual void GetLightColorReport(
+      uint8_t aRed, uint8_t aGreen, uint8_t aBlue,
+      std::vector<uint8_t>& aReport) const override {
+    const size_t report_length = 32;
+    aReport.resize(report_length);
+    aReport.assign(report_length, 0);
+
+    aReport[0] = 0x05;  // report ID USB only
+    aReport[1] = 0x02;  // LED only
+    aReport[6] = aRed;
+    aReport[7] = aGreen;
+    aReport[8] = aBlue;
+  }
+
+  virtual uint32_t GetMaxInputReportLength() const override {
+    return MAX_INPUT_LEN;
+  }
+
+  virtual void ProcessTouchData(GamepadHandle aHandle, void* aInput) override {
+    nsTArray<GamepadTouchState> touches(TOUCH_EVENT_COUNT);
+    touches.SetLength(TOUCH_EVENT_COUNT);
+    uint8_t* rawData = (uint8_t*)aInput;
+
+    const uint32_t kTouchDimensionX = 1920;
+    const uint32_t kTouchDimensionY = 942;
+    bool touch0Pressed = (((rawData[35] & 0xff) >> 7) == 0);
+    bool touch1Pressed = (((rawData[39] & 0xff) >> 7) == 0);
+
+    if ((touch0Pressed && (rawData[35] & 0xff) < mLastTouchId[0]) ||
+        (touch1Pressed && (rawData[39] & 0xff) < mLastTouchId[1])) {
+      mTouchIdBase += 128;
+    }
+
+    if (touch0Pressed) {
+      touches[0].touchId = mTouchIdBase + (rawData[35] & 0x7f);
+      touches[0].surfaceId = 0;
+      touches[0].position[0] = NormalizeTouch(
+          ((rawData[37] & 0xf) << 8) | rawData[36], 0, (kTouchDimensionX - 1));
+      touches[0].position[1] =
+          NormalizeTouch(rawData[38] << 4 | ((rawData[37] & 0xf0) >> 4), 0,
+                         (kTouchDimensionY - 1));
+      touches[0].surfaceDimensions[0] = kTouchDimensionX;
+      touches[0].surfaceDimensions[1] = kTouchDimensionY;
+      touches[0].isSurfaceDimensionsValid = true;
+      mLastTouchId[0] = rawData[35] & 0x7f;
+    }
+    if (touch1Pressed) {
+      touches[1].touchId = mTouchIdBase + (rawData[39] & 0x7f);
+      touches[1].surfaceId = 0;
+      touches[1].position[0] =
+          NormalizeTouch((((rawData[41] & 0xf) << 8) | rawData[40]) + 1, 0,
+                         (kTouchDimensionX - 1));
+      touches[1].position[1] =
+          NormalizeTouch(rawData[42] << 4 | ((rawData[41] & 0xf0) >> 4), 0,
+                         (kTouchDimensionY - 1));
+      touches[1].surfaceDimensions[0] = kTouchDimensionX;
+      touches[1].surfaceDimensions[1] = kTouchDimensionY;
+      touches[1].isSurfaceDimensionsValid = true;
+      mLastTouchId[1] = rawData[39] & 0x7f;
+    }
+
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    // Avoid to send duplicate untouched events to the gamepad service.
+    if ((mLastTouches[0] != touch0Pressed) || touch0Pressed) {
+      service->NewMultiTouchEvent(aHandle, 0, touches[0]);
+    }
+    if ((mLastTouches[1] != touch1Pressed) || touch1Pressed) {
+      service->NewMultiTouchEvent(aHandle, 1, touches[1]);
+    }
+    mLastTouches[0] = touch0Pressed;
+    mLastTouches[1] = touch1Pressed;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 3: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 4: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 5:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 9:
+        FetchDpadFromAxis(aHandle, aValue);
+        break;
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in Dualshock4Remapper().", aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    constexpr std::array<uint32_t, 14> buttonMapping = {
+        BUTTON_INDEX_TERTIARY,
+        BUTTON_INDEX_PRIMARY,
+        BUTTON_INDEX_SECONDARY,
+        BUTTON_INDEX_QUATERNARY,
+        BUTTON_INDEX_LEFT_SHOULDER,
+        BUTTON_INDEX_RIGHT_SHOULDER,
+        BUTTON_INDEX_LEFT_TRIGGER,
+        BUTTON_INDEX_RIGHT_TRIGGER,
+        BUTTON_INDEX_BACK_SELECT,
+        BUTTON_INDEX_START,
+        BUTTON_INDEX_LEFT_THUMBSTICK,
+        BUTTON_INDEX_RIGHT_THUMBSTICK,
+        BUTTON_INDEX_META,
+        DUALSHOCK_BUTTON_TOUCHPAD};
+
+    if (buttonMapping.size() <= aButton) {
+      NS_WARNING(nsPrintfCString(
+                     "Button idx '%d' doesn't support in Dualshock4Remapper().",
+                     aButton)
+                     .get());
+      return;
+    }
+
+    service->NewButtonEvent(aHandle, buttonMapping[aButton], aPressed);
+  }
+
+ private:
+  enum Dualshock4Buttons {
+    DUALSHOCK_BUTTON_TOUCHPAD = BUTTON_INDEX_COUNT,
+    DUALSHOCK_BUTTON_COUNT
+  };
+
+  static const uint32_t LIGHT_INDICATOR_COUNT = 1;
+  static const uint32_t TOUCH_EVENT_COUNT = 2;
+  static const uint32_t MAX_INPUT_LEN = 68;
+
+  nsTArray<unsigned long> mLastTouchId;
+  nsTArray<bool> mLastTouches;
+  unsigned long mTouchIdBase = 0;
+};
+
+class Xbox360Remapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return BUTTON_INDEX_COUNT;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 3:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 4:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 5: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in Xbox360Remapper().", aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in Xbox360Remapper().", aButton)
+              .get());
+      return;
+    }
+
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {6, BUTTON_INDEX_LEFT_THUMBSTICK}, {7, BUTTON_INDEX_RIGHT_THUMBSTICK},
+        {8, BUTTON_INDEX_START},           {9, BUTTON_INDEX_BACK_SELECT},
+        {10, BUTTON_INDEX_META},           {11, BUTTON_INDEX_DPAD_UP},
+        {12, BUTTON_INDEX_DPAD_DOWN},      {13, BUTTON_INDEX_DPAD_LEFT},
+        {14, BUTTON_INDEX_DPAD_RIGHT}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+};
+
+class XboxOneSRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return BUTTON_INDEX_COUNT;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 3:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 4:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 5: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 9:
+        FetchDpadFromAxis(aHandle, aValue);
+        break;
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in XboxOneSRemapper().", aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in XboxOneSRemapper().", aButton)
+              .get());
+      return;
+    }
+
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {6, BUTTON_INDEX_BACK_SELECT},
+        {7, BUTTON_INDEX_START},
+        {8, BUTTON_INDEX_LEFT_THUMBSTICK},
+        {9, BUTTON_INDEX_RIGHT_THUMBSTICK},
+        {10, BUTTON_INDEX_META}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+};
+
+class XboxOneS2016FirmwareRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return BUTTON_INDEX_COUNT;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 3: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 4: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 5:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 9:
+        FetchDpadFromAxis(aHandle, aValue);
+        break;
+      default:
+        NS_WARNING(nsPrintfCString("Axis idx '%d' doesn't support in "
+                                   "XboxOneS2016FirmwareRemapper().",
+                                   aAxis)
+                       .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(nsPrintfCString("Button idx '%d' doesn't support in "
+                                 "XboxOneS2016FirmwareRemapper().",
+                                 aButton)
+                     .get());
+      return;
+    }
+
+    // kMicrosoftProductXboxOneSWireless2016 controller received a firmware
+    // update in 2019 that changed which field is populated with the meta button
+    // state. In order to cover the old and new cases, we have to check both
+    // fields of {12, 15} buttons.
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {0, BUTTON_INDEX_PRIMARY},
+        {1, BUTTON_INDEX_SECONDARY},
+        {3, BUTTON_INDEX_TERTIARY},
+        {4, BUTTON_INDEX_QUATERNARY},
+        {6, BUTTON_INDEX_LEFT_SHOULDER},
+        {7, BUTTON_INDEX_RIGHT_SHOULDER},
+        {11, BUTTON_INDEX_START},
+        {12, BUTTON_INDEX_META},
+        {13, BUTTON_INDEX_LEFT_THUMBSTICK},
+        {14, BUTTON_INDEX_RIGHT_THUMBSTICK},
+        {15, BUTTON_INDEX_META},
+        {16, BUTTON_INDEX_BACK_SELECT}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+};
+
+class XboxOneRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return BUTTON_INDEX_COUNT;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 3:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 9:
+        FetchDpadFromAxis(aHandle, aValue);
+        break;
+      case 10: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 11: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in XboxOneRemapper().", aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in XboxOneRemapper().", aButton)
+              .get());
+      return;
+    }
+
+    // Accessing {30, 31} buttons looks strange to me
+    // and without an avilable device to help verify it.
+    // It is according to `MapperXboxOneBluetooth()` in
+    // https://cs.chromium.org/chromium/src/device/gamepad/gamepad_standard_mappings_mac.mm
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {0, BUTTON_INDEX_PRIMARY},
+        {1, BUTTON_INDEX_SECONDARY},
+        {3, BUTTON_INDEX_TERTIARY},
+        {4, BUTTON_INDEX_QUATERNARY},
+        {6, BUTTON_INDEX_LEFT_SHOULDER},
+        {7, BUTTON_INDEX_RIGHT_SHOULDER},
+        {11, BUTTON_INDEX_START},
+        {13, BUTTON_INDEX_LEFT_THUMBSTICK},
+        {14, BUTTON_INDEX_RIGHT_THUMBSTICK},
+        {30, BUTTON_INDEX_META},
+        {31, BUTTON_INDEX_BACK_SELECT}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+};
+
+class XboxSeriesXRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return BUTTON_INDEX_COUNT;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 5:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 9:
+        FetchDpadFromAxis(aHandle, aValue);
+        break;
+      case 148: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 149: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in XboxSeriesXRemapper().",
+                aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in XboxSeriesXRemapper().",
+              aButton)
+              .get());
+      return;
+    }
+
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {0, BUTTON_INDEX_PRIMARY},
+        {1, BUTTON_INDEX_SECONDARY},
+        {3, BUTTON_INDEX_TERTIARY},
+        {4, BUTTON_INDEX_QUATERNARY},
+        {6, BUTTON_INDEX_LEFT_SHOULDER},
+        {7, BUTTON_INDEX_RIGHT_SHOULDER},
+        {10, BUTTON_INDEX_BACK_SELECT},
+        {11, BUTTON_INDEX_START},
+        {12, BUTTON_INDEX_META},
+        {13, BUTTON_INDEX_LEFT_THUMBSTICK},
+        {14, BUTTON_INDEX_RIGHT_THUMBSTICK}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+};
+
+class LogitechDInputRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    // The Logitech button (BUTTON_INDEX_META) is not accessible through the
+    // device's D-mode.
+    return BUTTON_INDEX_COUNT - 1;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 5:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 9:
+        FetchDpadFromAxis(aHandle, aValue);
+        break;
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in LogitechDInputRemapper().",
+                aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in LogitechDInputRemapper().",
+              aButton)
+              .get());
+      return;
+    }
+
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {0, BUTTON_INDEX_TERTIARY},
+        {1, BUTTON_INDEX_PRIMARY},
+        {2, BUTTON_INDEX_SECONDARY}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+};
+
+class SwitchJoyConRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return 2; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return BUTTON_INDEX_COUNT;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    if (GetAxisCount() <= aAxis) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Axis idx '%d' doesn't support in SwitchJoyConRemapper().", aAxis)
+              .get());
+      return;
+    }
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    service->NewButtonEvent(aHandle, aButton, aPressed);
+  }
+};
+
+class SwitchProRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    // The Switch Pro controller has a Capture button that has no equivalent in
+    // the Standard Gamepad.
+    return SWITCHPRO_BUTTON_COUNT;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    if (GetAxisCount() <= aAxis) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Axis idx '%d' doesn't support in SwitchProRemapper().", aAxis)
+              .get());
+      return;
+    }
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    service->NewButtonEvent(aHandle, aButton, aPressed);
+  }
+
+ private:
+  enum SwitchProButtons {
+    SWITCHPRO_BUTTON_EXTRA = BUTTON_INDEX_COUNT,
+    SWITCHPRO_BUTTON_COUNT
+  };
+};
+
+class NvShieldRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return SHIELD_BUTTON_COUNT;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 3: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 4: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 5:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 9:
+        FetchDpadFromAxis(aHandle, aValue);
+        break;
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in NvShieldRemapper().", aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in NvShieldRemapper().", aButton)
+              .get());
+      return;
+    }
+
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {2, BUTTON_INDEX_META},
+        {3, BUTTON_INDEX_TERTIARY},
+        {4, BUTTON_INDEX_QUATERNARY},
+        {5, SHIELD_BUTTON_CIRCLE},
+        {6, BUTTON_INDEX_LEFT_SHOULDER},
+        {7, BUTTON_INDEX_RIGHT_SHOULDER},
+        {9, BUTTON_INDEX_BACK_SELECT},
+        {11, BUTTON_INDEX_START},
+        {13, BUTTON_INDEX_LEFT_THUMBSTICK},
+        {14, BUTTON_INDEX_RIGHT_THUMBSTICK}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+
+ private:
+  enum ShieldButtons {
+    SHIELD_BUTTON_CIRCLE = BUTTON_INDEX_COUNT,
+    SHIELD_BUTTON_COUNT
+  };
+};
+
+class NvShield2017Remapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return SHIELD2017_BUTTON_COUNT;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 3: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 4: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 5:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 9:
+        FetchDpadFromAxis(aHandle, aValue);
+        break;
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in NvShield2017Remapper().",
+                aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in NvShield2017Remapper().",
+              aButton)
+              .get());
+      return;
+    }
+
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {2, BUTTON_INDEX_META},
+        {3, BUTTON_INDEX_TERTIARY},
+        {4, BUTTON_INDEX_QUATERNARY},
+        {5, BUTTON_INDEX_START},
+        {6, BUTTON_INDEX_LEFT_SHOULDER},
+        {7, BUTTON_INDEX_RIGHT_SHOULDER},
+        {8, BUTTON_INDEX_BACK_SELECT},
+        {11, SHIELD2017_BUTTON_PLAYPAUSE},
+        {13, BUTTON_INDEX_LEFT_THUMBSTICK},
+        {14, BUTTON_INDEX_RIGHT_THUMBSTICK}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+
+ private:
+  enum Shield2017Buttons {
+    SHIELD2017_BUTTON_PLAYPAUSE = BUTTON_INDEX_COUNT,
+    SHIELD2017_BUTTON_COUNT
+  };
+};
+
+class IBuffaloRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return 2; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return BUTTON_INDEX_COUNT - 1; /* no meta */
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_DPAD_LEFT,
+                                AxisNegativeAsButton(aValue));
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_DPAD_RIGHT,
+                                AxisPositiveAsButton(aValue));
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_DPAD_UP,
+                                AxisNegativeAsButton(aValue));
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_DPAD_DOWN,
+                                AxisPositiveAsButton(aValue));
+        break;
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in IBuffaloRemapper().", aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in IBuffaloRemapper().", aButton)
+              .get());
+      return;
+    }
+
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {0, BUTTON_INDEX_SECONDARY},     {1, BUTTON_INDEX_PRIMARY},
+        {2, BUTTON_INDEX_QUATERNARY},    {3, BUTTON_INDEX_TERTIARY},
+        {5, BUTTON_INDEX_RIGHT_TRIGGER}, {6, BUTTON_INDEX_BACK_SELECT},
+        {7, BUTTON_INDEX_START}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+};
+
+class XSkillsRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return GAMECUBE_BUTTON_COUNT;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 3: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 4: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 5:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in XSkillsRemapper().", aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in XSkillsRemapper().", aButton)
+              .get());
+      return;
+    }
+
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {0, BUTTON_INDEX_PRIMARY},     // A
+        {1, BUTTON_INDEX_TERTIARY},    // B
+        {2, BUTTON_INDEX_SECONDARY},   // X
+        {3, BUTTON_INDEX_QUATERNARY},  // Y
+        {4, GAMECUBE_BUTTON_LEFT_TRIGGER_CLICK},
+        {5, GAMECUBE_BUTTON_RIGHT_TRIGGER_CLICK},
+        {6, BUTTON_INDEX_RIGHT_SHOULDER},
+        {7, BUTTON_INDEX_START},
+        {8, BUTTON_INDEX_DPAD_LEFT},
+        {9, BUTTON_INDEX_DPAD_RIGHT},
+        {10, BUTTON_INDEX_DPAD_DOWN},
+        {11, BUTTON_INDEX_DPAD_UP}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+
+ private:
+  enum GamecubeButtons {
+    GAMECUBE_BUTTON_LEFT_TRIGGER_CLICK = BUTTON_INDEX_COUNT,
+    GAMECUBE_BUTTON_RIGHT_TRIGGER_CLICK,
+    GAMECUBE_BUTTON_COUNT
+  };
+};
+
+class BoomN64PsxRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return BUTTON_INDEX_COUNT - 1;  // no meta
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 5:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in BoomN64PsxRemapper().", aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    static constexpr std::array buttonMapping = {
+        BUTTON_INDEX_QUATERNARY,       BUTTON_INDEX_SECONDARY,
+        BUTTON_INDEX_PRIMARY,          BUTTON_INDEX_TERTIARY,
+        BUTTON_INDEX_LEFT_TRIGGER,     BUTTON_INDEX_RIGHT_TRIGGER,
+        BUTTON_INDEX_LEFT_SHOULDER,    BUTTON_INDEX_RIGHT_SHOULDER,
+        BUTTON_INDEX_BACK_SELECT,      BUTTON_INDEX_LEFT_THUMBSTICK,
+        BUTTON_INDEX_RIGHT_THUMBSTICK, BUTTON_INDEX_START,
+        BUTTON_INDEX_DPAD_UP,          BUTTON_INDEX_DPAD_RIGHT,
+        BUTTON_INDEX_DPAD_DOWN,        BUTTON_INDEX_DPAD_LEFT};
+
+    if (buttonMapping.size() <= aButton) {
+      NS_WARNING(nsPrintfCString(
+                     "Button idx '%d' doesn't support in BoomN64PsxRemapper().",
+                     aButton)
+                     .get());
+      return;
+    }
+
+    service->NewButtonEvent(aHandle, buttonMapping[aButton], aPressed);
+  }
+
+ private:
+  enum GamecubeButtons {
+    GAMECUBE_BUTTON_LEFT_TRIGGER_CLICK = BUTTON_INDEX_COUNT,
+    GAMECUBE_BUTTON_RIGHT_TRIGGER_CLICK,
+    GAMECUBE_BUTTON_COUNT
+  };
+};
+
+class StadiaControllerOldFirmwareRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return ANALOG_GAMEPAD_BUTTON_COUNT;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 3: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 4: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 5:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 9:
+        FetchDpadFromAxis(aHandle, aValue);
+        break;
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in AnalogGamepadRemapper().",
+                aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in AnalogGamepadRemapper().",
+              aButton)
+              .get());
+      return;
+    }
+
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {3, BUTTON_INDEX_TERTIARY},
+        {4, BUTTON_INDEX_QUATERNARY},
+        {6, BUTTON_INDEX_LEFT_SHOULDER},
+        {7, BUTTON_INDEX_RIGHT_SHOULDER},
+        {10, BUTTON_INDEX_BACK_SELECT},
+        {11, BUTTON_INDEX_META},
+        {12, BUTTON_INDEX_START},
+        {13, BUTTON_INDEX_LEFT_THUMBSTICK},
+        {14, BUTTON_INDEX_RIGHT_THUMBSTICK},
+        {16, ANALOG_GAMEPAD_BUTTON_EXTRA},
+        {17, ANALOG_GAMEPAD_BUTTON_EXTRA2}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+
+ private:
+  enum AnalogGamepadButtons {
+    ANALOG_GAMEPAD_BUTTON_EXTRA = BUTTON_INDEX_COUNT,
+    ANALOG_GAMEPAD_BUTTON_EXTRA2,
+    ANALOG_GAMEPAD_BUTTON_COUNT
+  };
+};
+
+class RazerServalRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return BUTTON_INDEX_COUNT - 1; /* no meta */
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 3: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 4: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 5:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 9:
+        FetchDpadFromAxis(aHandle, aValue);
+        break;
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in RazerServalRemapper().",
+                aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in RazerServalRemapper().",
+              aButton)
+              .get());
+      return;
+    }
+
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {3, BUTTON_INDEX_TERTIARY},         {4, BUTTON_INDEX_QUATERNARY},
+        {6, BUTTON_INDEX_LEFT_SHOULDER},    {7, BUTTON_INDEX_RIGHT_SHOULDER},
+        {10, BUTTON_INDEX_BACK_SELECT},     {11, BUTTON_INDEX_START},
+        {12, BUTTON_INDEX_START},           {13, BUTTON_INDEX_LEFT_THUMBSTICK},
+        {14, BUTTON_INDEX_RIGHT_THUMBSTICK}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+};
+
+class MogaProRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return BUTTON_INDEX_COUNT - 1; /* no meta */
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 3: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 4: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 5:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 9:
+        FetchDpadFromAxis(aHandle, aValue);
+        break;
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in MogaProRemapper().", aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in MogaProRemapper().", aButton)
+              .get());
+      return;
+    }
+
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {3, BUTTON_INDEX_TERTIARY},         {4, BUTTON_INDEX_QUATERNARY},
+        {6, BUTTON_INDEX_LEFT_SHOULDER},    {7, BUTTON_INDEX_RIGHT_SHOULDER},
+        {11, BUTTON_INDEX_START},           {13, BUTTON_INDEX_LEFT_THUMBSTICK},
+        {14, BUTTON_INDEX_RIGHT_THUMBSTICK}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+};
+
+class OnLiveWirelessRemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return BUTTON_INDEX_COUNT;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 3:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 4:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 5: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 9:
+        FetchDpadFromAxis(aHandle, aValue);
+        break;
+      default:
+        NS_WARNING(
+            nsPrintfCString(
+                "Axis idx '%d' doesn't support in OnLiveWirelessRemapper().",
+                aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString(
+              "Button idx '%d' doesn't support in OnLiveWirelessRemapper().",
+              aButton)
+              .get());
+      return;
+    }
+
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {3, BUTTON_INDEX_TERTIARY},
+        {4, BUTTON_INDEX_QUATERNARY},
+        {6, BUTTON_INDEX_LEFT_SHOULDER},
+        {7, BUTTON_INDEX_RIGHT_SHOULDER},
+        {12, BUTTON_INDEX_META},
+        {13, BUTTON_INDEX_LEFT_THUMBSTICK},
+        {14, BUTTON_INDEX_RIGHT_THUMBSTICK}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+};
+
+class OUYARemapper final : public GamepadRemapper {
+ public:
+  virtual uint32_t GetAxisCount() const override { return AXIS_INDEX_COUNT; }
+
+  virtual uint32_t GetButtonCount() const override {
+    return BUTTON_INDEX_COUNT;
+  }
+
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    switch (aAxis) {
+      case 0:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_X, aValue);
+        break;
+      case 1:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_LEFT_STICK_Y, aValue);
+        break;
+      case 2: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_LEFT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      case 3:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_X, aValue);
+        break;
+      case 4:
+        service->NewAxisMoveEvent(aHandle, AXIS_INDEX_RIGHT_STICK_Y, aValue);
+        break;
+      case 5: {
+        const double value = AxisToButtonValue(aValue);
+        service->NewButtonEvent(aHandle, BUTTON_INDEX_RIGHT_TRIGGER,
+                                value > BUTTON_THRESHOLD_VALUE, value);
+        break;
+      }
+      default:
+        NS_WARNING(
+            nsPrintfCString("Axis idx '%d' doesn't support in OUYARemapper().",
+                            aAxis)
+                .get());
+        break;
+    }
+  }
+
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const override {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    if (GetButtonCount() <= aButton) {
+      NS_WARNING(
+          nsPrintfCString("Button idx '%d' doesn't support in OUYARemapper().",
+                          aButton)
+              .get());
+      return;
+    }
+
+    const std::unordered_map<uint32_t, uint32_t> buttonMapping = {
+        {1, BUTTON_INDEX_TERTIARY},         {2, BUTTON_INDEX_QUATERNARY},
+        {3, BUTTON_INDEX_SECONDARY},        {6, BUTTON_INDEX_LEFT_THUMBSTICK},
+        {7, BUTTON_INDEX_RIGHT_THUMBSTICK}, {8, BUTTON_INDEX_DPAD_UP},
+        {9, BUTTON_INDEX_DPAD_DOWN},        {10, BUTTON_INDEX_DPAD_LEFT},
+        {11, BUTTON_INDEX_DPAD_RIGHT},      {15, BUTTON_INDEX_META}};
+
+    auto find = buttonMapping.find(aButton);
+    if (find != buttonMapping.end()) {
+      service->NewButtonEvent(aHandle, find->second, aPressed);
+    } else {
+      service->NewButtonEvent(aHandle, aButton, aPressed);
+    }
+  }
+};
+
+already_AddRefed<GamepadRemapper> GetGamepadRemapper(const uint16_t aVendorId,
+                                                     const uint16_t aProductId,
+                                                     bool& aUsingDefault) {
+  const std::vector<GamepadRemappingData> remappingRules = {
+      {GamepadId::kAsusTekProduct4500, new ADT1Remapper()},
+      {GamepadId::kDragonRiseProduct0011, new TwoAxesEightKeysRemapper()},
+      {GamepadId::kGoogleProduct2c40, new ADT1Remapper()},
+      {GamepadId::kGoogleProduct9400, new StadiaControllerRemapper()},
+      {GamepadId::kLogitechProductc216, new LogitechDInputRemapper()},
+      {GamepadId::kLogitechProductc218, new LogitechDInputRemapper()},
+      {GamepadId::kLogitechProductc219, new LogitechDInputRemapper()},
+      {GamepadId::kMicrosoftProductXbox360Wireless, new Xbox360Remapper()},
+      {GamepadId::kMicrosoftProductXbox360Wireless2, new Xbox360Remapper()},
+      {GamepadId::kMicrosoftProductXboxOneElite2Wireless,
+       new XboxOneRemapper()},
+      {GamepadId::kMicrosoftProductXboxOneSWireless, new XboxOneSRemapper()},
+      {GamepadId::kMicrosoftProductXboxOneSWireless2016,
+       new XboxOneS2016FirmwareRemapper()},
+      {GamepadId::kMicrosoftProductXboxAdaptiveWireless, new XboxOneRemapper()},
+      {GamepadId::kMicrosoftProductXboxSeriesXWireless,
+       new XboxSeriesXRemapper()},
+      {GamepadId::kNintendoProduct2006, new SwitchJoyConRemapper()},
+      {GamepadId::kNintendoProduct2007, new SwitchJoyConRemapper()},
+      {GamepadId::kNintendoProduct2009, new SwitchProRemapper()},
+      {GamepadId::kNintendoProduct200e, new SwitchProRemapper()},
+      {GamepadId::kNvidiaProduct7210, new NvShieldRemapper()},
+      {GamepadId::kNvidiaProduct7214, new NvShield2017Remapper()},
+      {GamepadId::kPadixProduct2060, new IBuffaloRemapper()},
+      {GamepadId::kPlayComProduct0005, new XSkillsRemapper()},
+      {GamepadId::kPrototypeVendorProduct0667, new BoomN64PsxRemapper()},
+      {GamepadId::kPrototypeVendorProduct9401,
+       new StadiaControllerOldFirmwareRemapper()},
+      {GamepadId::kRazer1532Product0900, new RazerServalRemapper()},
+      {GamepadId::kSonyProduct0268, new Playstation3Remapper()},
+      {GamepadId::kSonyProduct05c4, new Dualshock4Remapper()},
+      {GamepadId::kSonyProduct09cc, new Dualshock4Remapper()},
+      {GamepadId::kSonyProduct0ba0, new Dualshock4Remapper()},
+      {GamepadId::kVendor20d6Product6271, new MogaProRemapper()},
+      {GamepadId::kVendor2378Product1008, new OnLiveWirelessRemapper()},
+      {GamepadId::kVendor2378Product100a, new OnLiveWirelessRemapper()},
+      {GamepadId::kVendor2836Product0001, new OUYARemapper()}};
+  const GamepadId id = static_cast<GamepadId>((aVendorId << 16) | aProductId);
+
+  for (uint32_t i = 0; i < remappingRules.size(); ++i) {
+    if (id == remappingRules[i].id) {
+      aUsingDefault = false;
+      return do_AddRef(remappingRules[i].remapping.get());
+    }
+  }
+
+  RefPtr<GamepadRemapper> defaultRemapper = new DefaultRemapper();
+  aUsingDefault = true;
+  return do_AddRef(defaultRemapper.get());
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/GamepadRemapping.h b/dom/gamepad/GamepadRemapping.h
new file mode 100644
index 0000000000..0a508fe134
--- /dev/null
+++ b/dom/gamepad/GamepadRemapping.h
@@ -0,0 +1,177 @@
+/* -*- 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_GamepadRemapping_h_
+#define mozilla_dom_GamepadRemapping_h_
+
+#include "mozilla/dom/GamepadBinding.h"
+#include "mozilla/dom/GamepadLightIndicator.h"
+#include "mozilla/dom/GamepadPoseState.h"
+#include "mozilla/dom/GamepadTouchState.h"
+
+namespace mozilla::dom {
+
+// GamepadId is (vendorId << 16) | productId)
+enum class GamepadId : uint32_t {
+  // Nexus Player Controller
+  kAsusTekProduct4500 = 0x0b054500,
+  // 2Axes 8Keys Game Pad
+  kDragonRiseProduct0011 = 0x00790011,
+  // ADT-1 Controller
+  kGoogleProduct2c40 = 0x18d12c40,
+  // Stadia Controller
+  kGoogleProduct9400 = 0x18d19400,
+  // Logitech F310, D-mode
+  kLogitechProductc216 = 0x046dc216,
+  // Logitech F510, D-mode
+  kLogitechProductc218 = 0x046dc218,
+  // Logitech F710, D-mode
+  kLogitechProductc219 = 0x046dc219,
+  // Microsoft Xbox 360
+  kMicrosoftProductXbox360 = 0x045e028e,
+  // Microsoft Xbox 360 Wireless
+  kMicrosoftProductXbox360Wireless = 0x045e028f,
+  // Microsoft Xbox 360 Wireless
+  kMicrosoftProductXbox360Wireless2 = 0x045e0719,
+  // Microsoft Xbox One 2013
+  kMicrosoftProductXbox2013 = 0x045e02d1,
+  // Microsoft Xbox One (2015 FW)
+  kMicrosoftProductXbox2015 = 0x045e02dd,
+  // Microsoft Xbox One S
+  kMicrosoftProductXboxOneS = 0x045e02ea,
+  // Microsoft Xbox One S Wireless
+  kMicrosoftProductXboxOneSWireless = 0x045e02e0,
+  // Microsoft Xbox One Elite
+  kMicrosoftProductXboxOneElite = 0x045e02e3,
+  // Microsoft Xbox One Elite 2
+  kMicrosoftProductXboxOneElite2 = 0x045e0b00,
+  // Microsoft Xbox One Elite 2 Wireless
+  kMicrosoftProductXboxOneElite2Wireless = 0x045e0b05,
+  // Xbox One S Wireless (2016 FW)
+  kMicrosoftProductXboxOneSWireless2016 = 0x045e02fd,
+  // Microsoft Xbox Adaptive
+  kMicrosoftProductXboxAdaptive = 0x045e0b0a,
+  // Microsoft Xbox Adaptive Wireless
+  kMicrosoftProductXboxAdaptiveWireless = 0x045e0b0c,
+  // Microsoft Xbox Series X Wireless
+  kMicrosoftProductXboxSeriesXWireless = 0x045e0b13,
+  // Switch Joy-Con L
+  kNintendoProduct2006 = 0x057e2006,
+  // Switch Joy-Con R
+  kNintendoProduct2007 = 0x057e2007,
+  // Switch Pro Controller
+  kNintendoProduct2009 = 0x057e2009,
+  // Switch Charging Grip
+  kNintendoProduct200e = 0x057e200e,
+  // Nvidia Shield gamepad (2015)
+  kNvidiaProduct7210 = 0x09557210,
+  // Nvidia Shield gamepad (2017)
+  kNvidiaProduct7214 = 0x09557214,
+  // iBuffalo Classic
+  kPadixProduct2060 = 0x05832060,
+  // XSkills Gamecube USB adapter
+  kPlayComProduct0005 = 0x0b430005,
+  // boom PSX+N64 USB Converter
+  kPrototypeVendorProduct0667 = 0x66660667,
+  // Analog game controller
+  kPrototypeVendorProduct9401 = 0x66669401,
+  // Razer Serval Controller
+  kRazer1532Product0900 = 0x15320900,
+  // Playstation 3 Controller
+  kSonyProduct0268 = 0x054c0268,
+  // Playstation Dualshock 4
+  kSonyProduct05c4 = 0x054c05c4,
+  // Dualshock 4 (PS4 Slim)
+  kSonyProduct09cc = 0x054c09cc,
+  // Dualshock 4 USB receiver
+  kSonyProduct0ba0 = 0x054c0ba0,
+  // Moga Pro Controller (HID mode)
+  kVendor20d6Product6271 = 0x20d66271,
+  // OnLive Controller (Bluetooth)
+  kVendor2378Product1008 = 0x23781008,
+  // OnLive Controller (Wired)
+  kVendor2378Product100a = 0x2378100a,
+  // OUYA Controller
+  kVendor2836Product0001 = 0x28360001,
+};
+
+// Follow the canonical ordering recommendation for the "Standard Gamepad"
+// from https://www.w3.org/TR/gamepad/#remapping.
+enum CanonicalButtonIndex {
+  BUTTON_INDEX_PRIMARY,
+  BUTTON_INDEX_SECONDARY,
+  BUTTON_INDEX_TERTIARY,
+  BUTTON_INDEX_QUATERNARY,
+  BUTTON_INDEX_LEFT_SHOULDER,
+  BUTTON_INDEX_RIGHT_SHOULDER,
+  BUTTON_INDEX_LEFT_TRIGGER,
+  BUTTON_INDEX_RIGHT_TRIGGER,
+  BUTTON_INDEX_BACK_SELECT,
+  BUTTON_INDEX_START,
+  BUTTON_INDEX_LEFT_THUMBSTICK,
+  BUTTON_INDEX_RIGHT_THUMBSTICK,
+  BUTTON_INDEX_DPAD_UP,
+  BUTTON_INDEX_DPAD_DOWN,
+  BUTTON_INDEX_DPAD_LEFT,
+  BUTTON_INDEX_DPAD_RIGHT,
+  BUTTON_INDEX_META,
+  BUTTON_INDEX_COUNT
+};
+
+enum CanonicalAxisIndex {
+  AXIS_INDEX_LEFT_STICK_X,
+  AXIS_INDEX_LEFT_STICK_Y,
+  AXIS_INDEX_RIGHT_STICK_X,
+  AXIS_INDEX_RIGHT_STICK_Y,
+  AXIS_INDEX_COUNT
+};
+
+static inline bool AxisNegativeAsButton(double input) { return input < -0.5; }
+
+static inline bool AxisPositiveAsButton(double input) { return input > 0.5; }
+
+class GamepadRemapper {
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(GamepadRemapper)
+
+ public:
+  virtual uint32_t GetAxisCount() const = 0;
+  virtual uint32_t GetButtonCount() const = 0;
+  virtual uint32_t GetLightIndicatorCount() const { return 0; }
+  virtual void GetLightIndicators(
+      nsTArray<GamepadLightIndicatorType>& aTypes) const {}
+  virtual uint32_t GetTouchEventCount() const { return 0; }
+  virtual void GetLightColorReport(uint8_t aRed, uint8_t aGreen, uint8_t aBlue,
+                                   std::vector<uint8_t>& aReport) const {}
+  virtual uint32_t GetMaxInputReportLength() const { return 0; }
+
+  virtual void SetAxisCount(uint32_t aButtonCount) {}
+  virtual void SetButtonCount(uint32_t aButtonCount) {}
+  virtual GamepadMappingType GetMappingType() const {
+    return GamepadMappingType::Standard;
+  }
+  virtual void ProcessTouchData(GamepadHandle aHandle, void* aInput) {}
+  virtual void RemapAxisMoveEvent(GamepadHandle aHandle, uint32_t aAxis,
+                                  double aValue) const = 0;
+  virtual void RemapButtonEvent(GamepadHandle aHandle, uint32_t aButton,
+                                bool aPressed) const = 0;
+
+ protected:
+  GamepadRemapper() = default;
+  virtual ~GamepadRemapper() = default;
+};
+
+struct GamepadRemappingData {
+  GamepadId id;
+  RefPtr<GamepadRemapper> remapping;
+};
+
+already_AddRefed<GamepadRemapper> GetGamepadRemapper(const uint16_t aVendorId,
+                                                     const uint16_t aProductId,
+                                                     bool& aUsingDefault);
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_GamepadRemapping_h_
diff --git a/dom/gamepad/GamepadServiceTest.cpp b/dom/gamepad/GamepadServiceTest.cpp
new file mode 100644
index 0000000000..18998dcc4b
--- /dev/null
+++ b/dom/gamepad/GamepadServiceTest.cpp
@@ -0,0 +1,388 @@
+/* -*- 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 "GamepadServiceTest.h"
+
+#include "mozilla/ErrorResult.h"
+#include "mozilla/Unused.h"
+
+#include "mozilla/dom/GamepadManager.h"
+#include "mozilla/dom/GamepadPlatformService.h"
+#include "mozilla/dom/GamepadServiceTestBinding.h"
+#include "mozilla/dom/GamepadTestChannelChild.h"
+
+#include "mozilla/ipc/BackgroundChild.h"
+#include "mozilla/ipc/PBackgroundChild.h"
+
+namespace mozilla::dom {
+
+/*
+ * Implementation of the test service. This is just to provide a simple binding
+ * of the GamepadService to JavaScript via WebIDL so that we can write
+ * Mochitests that add and remove fake gamepads, avoiding the platform-specific
+ * backends.
+ */
+
+constexpr uint32_t kMaxButtons = 20;
+constexpr uint32_t kMaxAxes = 10;
+constexpr uint32_t kMaxHaptics = 2;
+constexpr uint32_t kMaxLightIndicator = 2;
+constexpr uint32_t kMaxTouchEvents = 4;
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(GamepadServiceTest, DOMEventTargetHelper,
+                                   mWindow)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(GamepadServiceTest)
+NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)
+
+NS_IMPL_ADDREF_INHERITED(GamepadServiceTest, DOMEventTargetHelper)
+NS_IMPL_RELEASE_INHERITED(GamepadServiceTest, DOMEventTargetHelper)
+
+// static
+already_AddRefed<GamepadServiceTest> GamepadServiceTest::CreateTestService(
+    nsPIDOMWindowInner* aWindow) {
+  MOZ_ASSERT(aWindow);
+  RefPtr<GamepadServiceTest> service = new GamepadServiceTest(aWindow);
+  service->InitPBackgroundActor();
+  return service.forget();
+}
+
+void GamepadServiceTest::Shutdown() {
+  MOZ_ASSERT(!mShuttingDown);
+  mShuttingDown = true;
+  DestroyPBackgroundActor();
+  mWindow = nullptr;
+}
+
+GamepadServiceTest::GamepadServiceTest(nsPIDOMWindowInner* aWindow)
+    : mService(GamepadManager::GetService()),
+      mWindow(aWindow),
+      mEventNumber(0),
+      mShuttingDown(false),
+      mChild(nullptr) {}
+
+GamepadServiceTest::~GamepadServiceTest() {
+  MOZ_ASSERT(mPromiseList.IsEmpty());
+}
+
+void GamepadServiceTest::InitPBackgroundActor() {
+  MOZ_ASSERT(!mChild);
+
+  ::mozilla::ipc::PBackgroundChild* actor =
+      ::mozilla::ipc::BackgroundChild::GetOrCreateForCurrentThread();
+  if (NS_WARN_IF(!actor)) {
+    MOZ_CRASH("Failed to create a PBackgroundChild actor!");
+  }
+
+  mChild = GamepadTestChannelChild::Create(this);
+  PGamepadTestChannelChild* initedChild =
+      actor->SendPGamepadTestChannelConstructor(mChild.get());
+  if (NS_WARN_IF(!initedChild)) {
+    MOZ_CRASH("Failed to create a PBackgroundChild actor!");
+  }
+}
+
+void GamepadServiceTest::ReplyGamepadHandle(uint32_t aPromiseId,
+                                            const GamepadHandle& aHandle) {
+  uint32_t handleSlot = AddGamepadHandle(aHandle);
+
+  RefPtr<Promise> p;
+  if (!mPromiseList.Get(aPromiseId, getter_AddRefs(p))) {
+    MOZ_CRASH("We should always have a promise.");
+  }
+
+  p->MaybeResolve(handleSlot);
+  mPromiseList.Remove(aPromiseId);
+}
+
+void GamepadServiceTest::DestroyPBackgroundActor() {
+  MOZ_ASSERT(mChild);
+  PGamepadTestChannelChild::Send__delete__(mChild);
+  mChild = nullptr;
+}
+
+already_AddRefed<Promise> GamepadServiceTest::AddGamepad(
+    const nsAString& aID, GamepadMappingType aMapping, GamepadHand aHand,
+    uint32_t aNumButtons, uint32_t aNumAxes, uint32_t aNumHaptics,
+    uint32_t aNumLightIndicator, uint32_t aNumTouchEvents, ErrorResult& aRv) {
+  if (aNumButtons > kMaxButtons || aNumAxes > kMaxAxes ||
+      aNumHaptics > kMaxHaptics || aNumLightIndicator > kMaxLightIndicator ||
+      aNumTouchEvents > kMaxTouchEvents) {
+    aRv.ThrowNotSupportedError("exceeded maximum hardware dimensions");
+    return nullptr;
+  }
+
+  if (mShuttingDown) {
+    aRv.ThrowInvalidStateError("Shutting down");
+    return nullptr;
+  }
+
+  // The values here are ignored, the value just can't be zero to avoid an
+  // assertion
+  GamepadHandle gamepadHandle{1, GamepadHandleKind::GamepadPlatformManager};
+
+  // Only VR controllers has displayID, we give 0 to the general gamepads.
+  GamepadAdded a(nsString(aID), aMapping, aHand, 0, aNumButtons, aNumAxes,
+                 aNumHaptics, aNumLightIndicator, aNumTouchEvents);
+  GamepadChangeEventBody body(a);
+  GamepadChangeEvent e(gamepadHandle, body);
+
+  RefPtr<Promise> p = Promise::Create(mWindow->AsGlobal(), aRv);
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  uint32_t id = ++mEventNumber;
+
+  MOZ_ASSERT(!mPromiseList.Contains(id));
+  mPromiseList.InsertOrUpdate(id, RefPtr{p});
+
+  mChild->SendGamepadTestEvent(id, e);
+
+  return p.forget();
+}
+
+already_AddRefed<Promise> GamepadServiceTest::RemoveGamepad(
+    uint32_t aHandleSlot, ErrorResult& aRv) {
+  if (mShuttingDown) {
+    aRv.ThrowInvalidStateError("Shutting down");
+    return nullptr;
+  }
+
+  GamepadHandle gamepadHandle = GetHandleInSlot(aHandleSlot);
+
+  GamepadRemoved a;
+  GamepadChangeEventBody body(a);
+  GamepadChangeEvent e(gamepadHandle, body);
+
+  uint32_t id = ++mEventNumber;
+
+  RefPtr<Promise> p = Promise::Create(mWindow->AsGlobal(), aRv);
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  MOZ_ASSERT(!mPromiseList.Contains(id));
+  mPromiseList.InsertOrUpdate(id, RefPtr{p});
+
+  mChild->SendGamepadTestEvent(id, e);
+  return p.forget();
+}
+
+already_AddRefed<Promise> GamepadServiceTest::NewButtonEvent(
+    uint32_t aHandleSlot, uint32_t aButton, bool aPressed, bool aTouched,
+    ErrorResult& aRv) {
+  if (mShuttingDown) {
+    aRv.ThrowInvalidStateError("Shutting down");
+    return nullptr;
+  }
+
+  GamepadHandle gamepadHandle = GetHandleInSlot(aHandleSlot);
+
+  GamepadButtonInformation a(aButton, aPressed ? 1.0 : 0, aPressed, aTouched);
+  GamepadChangeEventBody body(a);
+  GamepadChangeEvent e(gamepadHandle, body);
+
+  uint32_t id = ++mEventNumber;
+  RefPtr<Promise> p = Promise::Create(mWindow->AsGlobal(), aRv);
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  MOZ_ASSERT(!mPromiseList.Contains(id));
+  mPromiseList.InsertOrUpdate(id, RefPtr{p});
+  mChild->SendGamepadTestEvent(id, e);
+  return p.forget();
+}
+
+already_AddRefed<Promise> GamepadServiceTest::NewButtonValueEvent(
+    uint32_t aHandleSlot, uint32_t aButton, bool aPressed, bool aTouched,
+    double aValue, ErrorResult& aRv) {
+  if (mShuttingDown) {
+    aRv.ThrowInvalidStateError("Shutting down");
+    return nullptr;
+  }
+
+  GamepadHandle gamepadHandle = GetHandleInSlot(aHandleSlot);
+
+  GamepadButtonInformation a(aButton, aValue, aPressed, aTouched);
+  GamepadChangeEventBody body(a);
+  GamepadChangeEvent e(gamepadHandle, body);
+
+  uint32_t id = ++mEventNumber;
+  RefPtr<Promise> p = Promise::Create(mWindow->AsGlobal(), aRv);
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  MOZ_ASSERT(!mPromiseList.Contains(id));
+  mPromiseList.InsertOrUpdate(id, RefPtr{p});
+  mChild->SendGamepadTestEvent(id, e);
+  return p.forget();
+}
+
+already_AddRefed<Promise> GamepadServiceTest::NewAxisMoveEvent(
+    uint32_t aHandleSlot, uint32_t aAxis, double aValue, ErrorResult& aRv) {
+  if (mShuttingDown) {
+    aRv.ThrowInvalidStateError("Shutting down");
+    return nullptr;
+  }
+
+  GamepadHandle gamepadHandle = GetHandleInSlot(aHandleSlot);
+
+  GamepadAxisInformation a(aAxis, aValue);
+  GamepadChangeEventBody body(a);
+  GamepadChangeEvent e(gamepadHandle, body);
+
+  uint32_t id = ++mEventNumber;
+  RefPtr<Promise> p = Promise::Create(mWindow->AsGlobal(), aRv);
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  MOZ_ASSERT(!mPromiseList.Contains(id));
+  mPromiseList.InsertOrUpdate(id, RefPtr{p});
+  mChild->SendGamepadTestEvent(id, e);
+  return p.forget();
+}
+
+already_AddRefed<Promise> GamepadServiceTest::NewPoseMove(
+    uint32_t aHandleSlot, const Nullable<Float32Array>& aOrient,
+    const Nullable<Float32Array>& aPos,
+    const Nullable<Float32Array>& aAngVelocity,
+    const Nullable<Float32Array>& aAngAcceleration,
+    const Nullable<Float32Array>& aLinVelocity,
+    const Nullable<Float32Array>& aLinAcceleration, ErrorResult& aRv) {
+  if (mShuttingDown) {
+    aRv.ThrowInvalidStateError("Shutting down");
+    return nullptr;
+  }
+
+  GamepadHandle gamepadHandle = GetHandleInSlot(aHandleSlot);
+
+  GamepadPoseState poseState;
+  poseState.flags = GamepadCapabilityFlags::Cap_Orientation |
+                    GamepadCapabilityFlags::Cap_Position |
+                    GamepadCapabilityFlags::Cap_AngularAcceleration |
+                    GamepadCapabilityFlags::Cap_LinearAcceleration;
+  if (!aOrient.IsNull()) {
+    DebugOnly<bool> ok = aOrient.Value().CopyDataTo(poseState.orientation);
+    MOZ_ASSERT(
+        ok, "aOrient.Value().Length() != ArrayLength(poseState.orientation)");
+    poseState.isOrientationValid = true;
+  }
+  if (!aPos.IsNull()) {
+    DebugOnly<bool> ok = aPos.Value().CopyDataTo(poseState.position);
+    MOZ_ASSERT(ok, "aPos.Value().Length() != ArrayLength(poseState.position)");
+    poseState.isPositionValid = true;
+  }
+  if (!aAngVelocity.IsNull()) {
+    DebugOnly<bool> ok =
+        aAngVelocity.Value().CopyDataTo(poseState.angularVelocity);
+    MOZ_ASSERT(ok,
+               "aAngVelocity.Value().Length() != "
+               "ArrayLength(poseState.angularVelocity)");
+  }
+  if (!aAngAcceleration.IsNull()) {
+    DebugOnly<bool> ok =
+        aAngAcceleration.Value().CopyDataTo(poseState.angularAcceleration);
+    MOZ_ASSERT(ok,
+               "aAngAcceleration.Value().Length() != "
+               "ArrayLength(poseState.angularAcceleration)");
+  }
+  if (!aLinVelocity.IsNull()) {
+    DebugOnly<bool> ok =
+        aLinVelocity.Value().CopyDataTo(poseState.linearVelocity);
+    MOZ_ASSERT(ok,
+               "aLinVelocity.Value().Length() != "
+               "ArrayLength(poseState.linearVelocity)");
+  }
+  if (!aLinAcceleration.IsNull()) {
+    DebugOnly<bool> ok =
+        aLinAcceleration.Value().CopyDataTo(poseState.linearAcceleration);
+    MOZ_ASSERT(ok,
+               "aLinAcceleration.Value().Length() != "
+               "ArrayLength(poseState.linearAcceleration)");
+  }
+
+  GamepadPoseInformation a(poseState);
+  GamepadChangeEventBody body(a);
+  GamepadChangeEvent e(gamepadHandle, body);
+
+  uint32_t id = ++mEventNumber;
+  RefPtr<Promise> p = Promise::Create(mWindow->AsGlobal(), aRv);
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  MOZ_ASSERT(!mPromiseList.Contains(id));
+  mPromiseList.InsertOrUpdate(id, RefPtr{p});
+  mChild->SendGamepadTestEvent(id, e);
+  return p.forget();
+}
+
+already_AddRefed<Promise> GamepadServiceTest::NewTouch(
+    uint32_t aHandleSlot, uint32_t aTouchArrayIndex, uint32_t aTouchId,
+    uint8_t aSurfaceId, const Float32Array& aPos,
+    const Nullable<Float32Array>& aSurfDim, ErrorResult& aRv) {
+  if (mShuttingDown) {
+    aRv.ThrowInvalidStateError("Shutting down");
+    return nullptr;
+  }
+
+  GamepadHandle gamepadHandle = GetHandleInSlot(aHandleSlot);
+
+  GamepadTouchState touchState;
+  touchState.touchId = aTouchId;
+  touchState.surfaceId = aSurfaceId;
+  DebugOnly<bool> ok = aPos.CopyDataTo(touchState.position);
+  MOZ_ASSERT(ok, "aPos.Length() != ArrayLength(touchState.position)");
+
+  if (!aSurfDim.IsNull()) {
+    ok = aSurfDim.Value().CopyDataTo(touchState.surfaceDimensions);
+    MOZ_ASSERT(
+        ok, "aSurfDim.Length() != ArrayLength(touchState.surfaceDimensions)");
+    touchState.isSurfaceDimensionsValid = true;
+  }
+
+  GamepadTouchInformation a(aTouchArrayIndex, touchState);
+  GamepadChangeEventBody body(a);
+  GamepadChangeEvent e(gamepadHandle, body);
+
+  uint32_t id = ++mEventNumber;
+  RefPtr<Promise> p = Promise::Create(mWindow->AsGlobal(), aRv);
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  MOZ_ASSERT(!mPromiseList.Contains(id));
+  mPromiseList.InsertOrUpdate(id, RefPtr{p});
+  mChild->SendGamepadTestEvent(id, e);
+  return p.forget();
+}
+
+JSObject* GamepadServiceTest::WrapObject(JSContext* aCx,
+                                         JS::Handle<JSObject*> aGivenProto) {
+  return GamepadServiceTest_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+uint32_t GamepadServiceTest::AddGamepadHandle(GamepadHandle aHandle) {
+  uint32_t handleSlot = mGamepadHandles.Length();
+  mGamepadHandles.AppendElement(aHandle);
+  return handleSlot;
+}
+
+void GamepadServiceTest::RemoveGamepadHandle(uint32_t aHandleSlot) {
+  MOZ_ASSERT(aHandleSlot < mGamepadHandles.Length());
+  return mGamepadHandles.RemoveElementAt(aHandleSlot);
+}
+
+GamepadHandle GamepadServiceTest::GetHandleInSlot(uint32_t aHandleSlot) const {
+  MOZ_ASSERT(aHandleSlot < mGamepadHandles.Length());
+  return mGamepadHandles.ElementAt(aHandleSlot);
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/GamepadServiceTest.h b/dom/gamepad/GamepadServiceTest.h
new file mode 100644
index 0000000000..3b88ff178a
--- /dev/null
+++ b/dom/gamepad/GamepadServiceTest.h
@@ -0,0 +1,115 @@
+/* -*- 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_GamepadServiceTest_h_
+#define mozilla_dom_GamepadServiceTest_h_
+
+#include "mozilla/DOMEventTargetHelper.h"
+#include "mozilla/dom/GamepadBinding.h"
+#include "mozilla/dom/GamepadHandle.h"
+#include "mozilla/dom/TypedArray.h"
+#include "mozilla/WeakPtr.h"
+
+namespace mozilla::dom {
+
+class GamepadChangeEvent;
+class GamepadManager;
+class GamepadTestChannelChild;
+class Promise;
+
+// Service for testing purposes
+class GamepadServiceTest final : public DOMEventTargetHelper,
+                                 public SupportsWeakPtr {
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(GamepadServiceTest,
+                                           DOMEventTargetHelper)
+
+  GamepadMappingType NoMapping() const { return GamepadMappingType::_empty; }
+  GamepadMappingType StandardMapping() const {
+    return GamepadMappingType::Standard;
+  }
+  GamepadHand NoHand() const { return GamepadHand::_empty; }
+  GamepadHand LeftHand() const { return GamepadHand::Left; }
+  GamepadHand RightHand() const { return GamepadHand::Right; }
+
+  // IPC receiver
+  void ReplyGamepadHandle(uint32_t aPromiseId, const GamepadHandle& aHandle);
+
+  // Methods from GamepadServiceTest.webidl
+  already_AddRefed<Promise> AddGamepad(
+      const nsAString& aID, GamepadMappingType aMapping, GamepadHand aHand,
+      uint32_t aNumButtons, uint32_t aNumAxes, uint32_t aNumHaptics,
+      uint32_t aNumLightIndicator, uint32_t aNumTouchEvents, ErrorResult& aRv);
+
+  already_AddRefed<Promise> RemoveGamepad(uint32_t aHandleSlot,
+                                          ErrorResult& aRv);
+
+  already_AddRefed<Promise> NewButtonEvent(uint32_t aHandleSlot,
+                                           uint32_t aButton, bool aPressed,
+                                           bool aTouched, ErrorResult& aRv);
+
+  already_AddRefed<Promise> NewButtonValueEvent(uint32_t aHandleSlot,
+                                                uint32_t aButton, bool aPressed,
+                                                bool aTouched, double aValue,
+                                                ErrorResult& aRv);
+
+  already_AddRefed<Promise> NewAxisMoveEvent(uint32_t aHandleSlot,
+                                             uint32_t aAxis, double aValue,
+                                             ErrorResult& aRv);
+
+  already_AddRefed<Promise> NewPoseMove(
+      uint32_t aHandleSlot, const Nullable<Float32Array>& aOrient,
+      const Nullable<Float32Array>& aPos,
+      const Nullable<Float32Array>& aAngVelocity,
+      const Nullable<Float32Array>& aAngAcceleration,
+      const Nullable<Float32Array>& aLinVelocity,
+      const Nullable<Float32Array>& aLinAcceleration, ErrorResult& aRv);
+
+  already_AddRefed<Promise> NewTouch(uint32_t aHandleSlot,
+                                     uint32_t aTouchArrayIndex,
+                                     uint32_t aTouchId, uint8_t aSurfaceId,
+                                     const Float32Array& aPos,
+                                     const Nullable<Float32Array>& aSurfDim,
+                                     ErrorResult& aRv);
+
+  void Shutdown();
+
+  static already_AddRefed<GamepadServiceTest> CreateTestService(
+      nsPIDOMWindowInner* aWindow);
+  nsPIDOMWindowInner* GetParentObject() const { return mWindow; }
+  JSObject* WrapObject(JSContext* aCx,
+                       JS::Handle<JSObject*> aGivenProto) override;
+
+ private:
+  // Hold a reference to the gamepad service so we don't have to worry about
+  // execution order in tests.
+  RefPtr<GamepadManager> mService;
+  nsCOMPtr<nsPIDOMWindowInner> mWindow;
+  uint32_t mEventNumber;
+  bool mShuttingDown;
+
+  // IPDL Channel for us to send test events to GamepadPlatformService, it
+  // will only be used in this singleton class and deleted during the IPDL
+  // shutdown chain
+  RefPtr<GamepadTestChannelChild> mChild;
+  nsTArray<GamepadHandle> mGamepadHandles;
+
+  nsRefPtrHashtable<nsUint32HashKey, dom::Promise> mPromiseList;
+
+  explicit GamepadServiceTest(nsPIDOMWindowInner* aWindow);
+  ~GamepadServiceTest();
+  void InitPBackgroundActor();
+  void DestroyPBackgroundActor();
+
+  uint32_t AddGamepadHandle(GamepadHandle aHandle);
+  void RemoveGamepadHandle(uint32_t aHandleSlot);
+  GamepadHandle GetHandleInSlot(uint32_t aHandleSlot) const;
+};
+
+}  // namespace mozilla::dom
+
+#endif
diff --git a/dom/gamepad/GamepadTouch.cpp b/dom/gamepad/GamepadTouch.cpp
new file mode 100644
index 0000000000..87be8e6701
--- /dev/null
+++ b/dom/gamepad/GamepadTouch.cpp
@@ -0,0 +1,72 @@
+/* -*- 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 "mozilla/dom/GamepadTouch.h"
+
+#include "mozilla/HoldDropJSObjects.h"
+#include "mozilla/dom/GamepadManager.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/dom/TypedArray.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_WITH_JS_MEMBERS(GamepadTouch, (mParent),
+                                                      (mPosition,
+                                                       mSurfaceDimensions))
+
+GamepadTouch::GamepadTouch(nsISupports* aParent)
+    : mParent(aParent), mPosition(nullptr), mSurfaceDimensions(nullptr) {
+  mozilla::HoldJSObjects(this);
+  mTouchState = GamepadTouchState();
+}
+
+GamepadTouch::~GamepadTouch() { mozilla::DropJSObjects(this); }
+
+/* virtual */ JSObject* GamepadTouch::WrapObject(
+    JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
+  return GamepadTouch_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+void GamepadTouch::GetPosition(JSContext* aCx,
+                               JS::MutableHandle<JSObject*> aRetval,
+                               ErrorResult& aRv) {
+  mPosition = Float32Array::Create(aCx, this, mTouchState.position, aRv);
+  if (aRv.Failed()) {
+    return;
+  }
+
+  aRetval.set(mPosition);
+}
+
+void GamepadTouch::GetSurfaceDimensions(JSContext* aCx,
+                                        JS::MutableHandle<JSObject*> aRetval,
+                                        ErrorResult& aRv) {
+  if (mTouchState.isSurfaceDimensionsValid) {
+    mSurfaceDimensions =
+        Uint32Array::Create(aCx, this, mTouchState.surfaceDimensions, aRv);
+  } else {
+    mSurfaceDimensions = Uint32Array::Create(
+        aCx, this, std::size(mTouchState.surfaceDimensions), aRv);
+  }
+
+  if (!mSurfaceDimensions) {
+    aRv.NoteJSContextException(aCx);
+    return;
+  }
+
+  aRetval.set(mSurfaceDimensions);
+}
+
+void GamepadTouch::SetTouchState(const GamepadTouchState& aTouch) {
+  mTouchState = aTouch;
+}
+
+void GamepadTouch::Set(const GamepadTouch* aOther) {
+  MOZ_ASSERT(aOther);
+  mTouchState = aOther->mTouchState;
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/GamepadTouch.h b/dom/gamepad/GamepadTouch.h
new file mode 100644
index 0000000000..591905ed73
--- /dev/null
+++ b/dom/gamepad/GamepadTouch.h
@@ -0,0 +1,47 @@
+/* -*- 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_gamepad_GamepadTouch_h
+#define mozilla_dom_gamepad_GamepadTouch_h
+
+#include "mozilla/dom/GamepadTouchBinding.h"
+#include "mozilla/dom/GamepadTouchState.h"
+#include "nsWrapperCache.h"
+
+namespace mozilla::dom {
+
+class GamepadTouch final : public nsWrapperCache {
+ public:
+  explicit GamepadTouch(nsISupports* aParent);
+
+  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(GamepadTouch)
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(GamepadTouch)
+
+  nsISupports* GetParentObject() const { return mParent; }
+  virtual JSObject* WrapObject(JSContext* aCx,
+                               JS::Handle<JSObject*> aGivenProto) override;
+  uint32_t TouchId() const { return mTouchState.touchId; }
+  uint32_t SurfaceId() const { return mTouchState.surfaceId; }
+  void GetPosition(JSContext* aCx, JS::MutableHandle<JSObject*> aRetval,
+                   ErrorResult& aRv);
+  void GetSurfaceDimensions(JSContext* aCx,
+                            JS::MutableHandle<JSObject*> aRetval,
+                            ErrorResult& aRv);
+  void SetTouchState(const GamepadTouchState& aTouch);
+  void Set(const GamepadTouch* aOther);
+
+ private:
+  virtual ~GamepadTouch();
+
+  nsCOMPtr<nsISupports> mParent;
+  JS::Heap<JSObject*> mPosition;
+  JS::Heap<JSObject*> mSurfaceDimensions;
+  GamepadTouchState mTouchState;
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_gamepad_GamepadTouch_h
diff --git a/dom/gamepad/GamepadTouchState.h b/dom/gamepad/GamepadTouchState.h
new file mode 100644
index 0000000000..0af81a6451
--- /dev/null
+++ b/dom/gamepad/GamepadTouchState.h
@@ -0,0 +1,42 @@
+/* -*- 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_gamepad_GamepadTouchState_h_
+#define mozilla_dom_gamepad_GamepadTouchState_h_
+
+namespace mozilla::dom {
+
+struct GamepadTouchState {
+  uint32_t touchId;
+  uint32_t surfaceId;
+  float position[2];
+  uint32_t surfaceDimensions[2];
+  bool isSurfaceDimensionsValid;
+
+  GamepadTouchState()
+      : touchId(0),
+        surfaceId(0),
+        position{0, 0},
+        surfaceDimensions{0, 0},
+        isSurfaceDimensionsValid(false) {}
+
+  bool operator==(const GamepadTouchState& aTouch) const {
+    return touchId == aTouch.touchId && surfaceId == aTouch.surfaceId &&
+           position[0] == aTouch.position[0] &&
+           position[1] == aTouch.position[1] &&
+           surfaceDimensions[0] == aTouch.surfaceDimensions[0] &&
+           surfaceDimensions[1] == aTouch.surfaceDimensions[1] &&
+           isSurfaceDimensionsValid == aTouch.isSurfaceDimensionsValid;
+  }
+
+  bool operator!=(const GamepadTouchState& aTouch) const {
+    return !(*this == aTouch);
+  }
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_gamepad_GamepadTouchState_h_
diff --git a/dom/gamepad/android/AndroidGamepad.cpp b/dom/gamepad/android/AndroidGamepad.cpp
new file mode 100644
index 0000000000..8887d4ac43
--- /dev/null
+++ b/dom/gamepad/android/AndroidGamepad.cpp
@@ -0,0 +1,121 @@
+/* -*- 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/. */
+
+// TODO: Bug 680289, implement gamepad haptics for Android.
+// TODO: Bug 1523355, implement gamepad lighindicator and touch for
+// Android.
+
+#include "mozilla/java/AndroidGamepadManagerNatives.h"
+#include "mozilla/java/GeckoAppShellWrappers.h"
+#include "mozilla/dom/Gamepad.h"
+#include "mozilla/dom/GamepadHandle.h"
+#include "mozilla/dom/GamepadPlatformService.h"
+#include "mozilla/Tainting.h"
+#include "nsThreadUtils.h"
+
+using mozilla::dom::GamepadHandle;
+
+namespace mozilla {
+namespace dom {
+
+class AndroidGamepadManager final
+    : public java::AndroidGamepadManager::Natives<AndroidGamepadManager> {
+  AndroidGamepadManager() = delete;
+
+ public:
+  static jni::ByteArray::LocalRef NativeAddGamepad() {
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    MOZ_RELEASE_ASSERT(service);
+
+    const GamepadHandle gamepadHandle = service->AddGamepad(
+        "android", GamepadMappingType::Standard, GamepadHand::_empty,
+        kStandardGamepadButtons, kStandardGamepadAxes, 0, 0, 0);
+
+    return mozilla::jni::ByteArray::New(
+        reinterpret_cast<const int8_t*>(&gamepadHandle), sizeof(gamepadHandle));
+  }
+
+  static void NativeRemoveGamepad(jni::ByteArray::Param aGamepadHandleBytes) {
+    GamepadHandle handle = JNIByteArrayToGamepadHandle(aGamepadHandleBytes);
+
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    service->RemoveGamepad(handle);
+  }
+
+  static void OnButtonChange(jni::ByteArray::Param aGamepadHandleBytes,
+                             int32_t aButton, bool aPressed, float aValue) {
+    GamepadHandle handle = JNIByteArrayToGamepadHandle(aGamepadHandleBytes);
+
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    service->NewButtonEvent(handle, aButton, aPressed, aValue);
+  }
+
+  static void OnAxisChange(jni::ByteArray::Param aGamepadHandleBytes,
+                           jni::BooleanArray::Param aValid,
+                           jni::FloatArray::Param aValues) {
+    GamepadHandle handle = JNIByteArrayToGamepadHandle(aGamepadHandleBytes);
+
+    RefPtr<GamepadPlatformService> service =
+        GamepadPlatformService::GetParentService();
+    if (!service) {
+      return;
+    }
+
+    const auto& valid = aValid->GetElements();
+    const auto& values = aValues->GetElements();
+    MOZ_ASSERT(valid.Length() == values.Length());
+
+    for (size_t i = 0; i < values.Length(); i++) {
+      if (valid[i]) {
+        service->NewAxisMoveEvent(handle, i, values[i]);
+      }
+    }
+  }
+
+ private:
+  static GamepadHandle JNIByteArrayToGamepadHandle(
+      jni::ByteArray::Param aGamepadHandleBytes) {
+    MOZ_ASSERT(aGamepadHandleBytes->Length() == sizeof(GamepadHandle));
+
+    GamepadHandle gamepadHandle;
+    aGamepadHandleBytes->CopyTo(reinterpret_cast<int8_t*>(&gamepadHandle),
+                                sizeof(gamepadHandle));
+
+    return gamepadHandle;
+  }
+};
+
+void StartGamepadMonitoring() {
+  AndroidGamepadManager::Init();
+  java::AndroidGamepadManager::Start(
+      java::GeckoAppShell::GetApplicationContext());
+}
+
+void StopGamepadMonitoring() {
+  java::AndroidGamepadManager::Stop(
+      java::GeckoAppShell::GetApplicationContext());
+}
+
+void SetGamepadLightIndicatorColor(const Tainted<GamepadHandle>& aGamepadHandle,
+                                   const Tainted<uint32_t>& aLightColorIndex,
+                                   const uint8_t& aRed, const uint8_t& aGreen,
+                                   const uint8_t& aBlue) {
+  NS_WARNING("Android doesn't support gamepad light indicator.");
+}
+
+}  // namespace dom
+}  // namespace mozilla
diff --git a/dom/gamepad/cocoa/CocoaGamepad.cpp b/dom/gamepad/cocoa/CocoaGamepad.cpp
new file mode 100644
index 0000000000..544c2e42b7
--- /dev/null
+++ b/dom/gamepad/cocoa/CocoaGamepad.cpp
@@ -0,0 +1,665 @@
+/* -*- 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/. */
+
+// mostly derived from the Allegro source code at:
+// http://alleg.svn.sourceforge.net/viewvc/alleg/allegro/branches/4.9/src/macosx/hidjoy.m?revision=13760&view=markup
+
+#include "mozilla/dom/GamepadHandle.h"
+#include "mozilla/dom/GamepadPlatformService.h"
+#include "mozilla/dom/GamepadRemapping.h"
+#include "mozilla/ipc/BackgroundParent.h"
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/Sprintf.h"
+#include "mozilla/Tainting.h"
+#include "nsComponentManagerUtils.h"
+#include "nsITimer.h"
+#include "nsThreadUtils.h"
+#include <CoreFoundation/CoreFoundation.h>
+#include <IOKit/hid/IOHIDBase.h>
+#include <IOKit/hid/IOHIDKeys.h>
+#include <IOKit/hid/IOHIDManager.h>
+
+#include <stdio.h>
+#include <vector>
+
+namespace {
+
+using namespace mozilla;
+using namespace mozilla::dom;
+class DarwinGamepadService;
+
+DarwinGamepadService* gService = nullptr;
+
+struct Button {
+  int id;
+  bool analog;
+  IOHIDElementRef element;
+  CFIndex min;
+  CFIndex max;
+  bool pressed;
+
+  Button(int aId, IOHIDElementRef aElement, CFIndex aMin, CFIndex aMax)
+      : id(aId),
+        analog((aMax - aMin) > 1),
+        element(aElement),
+        min(aMin),
+        max(aMax),
+        pressed(false) {}
+};
+
+struct Axis {
+  int id;
+  IOHIDElementRef element;
+  uint32_t usagePage;
+  uint32_t usage;
+  CFIndex min;
+  CFIndex max;
+  double value;
+};
+
+// These values can be found in the USB HID Usage Tables:
+// http://www.usb.org/developers/hidpage
+const unsigned kDesktopUsagePage = 0x01;
+const unsigned kSimUsagePage = 0x02;
+const unsigned kAcceleratorUsage = 0xC4;
+const unsigned kBrakeUsage = 0xC5;
+const unsigned kJoystickUsage = 0x04;
+const unsigned kGamepadUsage = 0x05;
+const unsigned kAxisUsageMin = 0x30;
+const unsigned kAxisUsageMax = 0x35;
+const unsigned kDpadUsage = 0x39;
+const unsigned kButtonUsagePage = 0x09;
+const unsigned kConsumerPage = 0x0C;
+const unsigned kHomeUsage = 0x223;
+const unsigned kBackUsage = 0x224;
+
+// We poll it periodically,
+// 50ms is arbitrarily chosen.
+const uint32_t kDarwinGamepadPollInterval = 50;
+
+struct GamepadInputReportContext {
+  DarwinGamepadService* service;
+  size_t gamepadSlot;
+};
+
+class Gamepad {
+ private:
+  IOHIDDeviceRef mDevice;
+  nsTArray<Button> buttons;
+  nsTArray<Axis> axes;
+
+ public:
+  Gamepad() : mDevice(nullptr) {}
+
+  bool operator==(IOHIDDeviceRef device) const { return mDevice == device; }
+  bool empty() const { return mDevice == nullptr; }
+  void clear() {
+    mDevice = nullptr;
+    buttons.Clear();
+    axes.Clear();
+    mHandle = GamepadHandle{};
+  }
+  void init(IOHIDDeviceRef device, bool defaultRemapper);
+  void ReportChanged(uint8_t* report, CFIndex report_length);
+  size_t WriteOutputReport(const std::vector<uint8_t>& aReport) const;
+
+  size_t numButtons() { return buttons.Length(); }
+  size_t numAxes() { return axes.Length(); }
+
+  Button* lookupButton(IOHIDElementRef element) {
+    for (unsigned i = 0; i < buttons.Length(); i++) {
+      if (buttons[i].element == element) return &buttons[i];
+    }
+    return nullptr;
+  }
+
+  Axis* lookupAxis(IOHIDElementRef element) {
+    for (unsigned i = 0; i < axes.Length(); i++) {
+      if (axes[i].element == element) return &axes[i];
+    }
+    return nullptr;
+  }
+
+  GamepadHandle mHandle;
+  RefPtr<GamepadRemapper> mRemapper;
+  nsTArray<uint8_t> mInputReport;
+  UniquePtr<GamepadInputReportContext> mInputReportContext;
+};
+
+void Gamepad::init(IOHIDDeviceRef aDevice, bool aDefaultRemapper) {
+  clear();
+  mDevice = aDevice;
+
+  CFArrayRef elements =
+      IOHIDDeviceCopyMatchingElements(aDevice, nullptr, kIOHIDOptionsTypeNone);
+  CFIndex n = CFArrayGetCount(elements);
+  for (CFIndex i = 0; i < n; i++) {
+    IOHIDElementRef element =
+        (IOHIDElementRef)CFArrayGetValueAtIndex(elements, i);
+    uint32_t usagePage = IOHIDElementGetUsagePage(element);
+    uint32_t usage = IOHIDElementGetUsage(element);
+
+    if (usagePage == kDesktopUsagePage && usage >= kAxisUsageMin &&
+        usage <= kAxisUsageMax) {
+      Axis axis = {aDefaultRemapper ? int(axes.Length())
+                                    : static_cast<int>(usage - kAxisUsageMin),
+                   element,
+                   usagePage,
+                   usage,
+                   IOHIDElementGetLogicalMin(element),
+                   IOHIDElementGetLogicalMax(element)};
+      axes.AppendElement(axis);
+    } else if (usagePage == kDesktopUsagePage && usage == kDpadUsage &&
+               // Don't know how to handle d-pads that return weird values.
+               IOHIDElementGetLogicalMax(element) -
+                       IOHIDElementGetLogicalMin(element) ==
+                   7) {
+      Axis axis = {aDefaultRemapper ? int(axes.Length())
+                                    : static_cast<int>(usage - kAxisUsageMin),
+                   element,
+                   usagePage,
+                   usage,
+                   IOHIDElementGetLogicalMin(element),
+                   IOHIDElementGetLogicalMax(element)};
+      axes.AppendElement(axis);
+    } else if (usagePage == kSimUsagePage &&
+               (usage == kAcceleratorUsage || usage == kBrakeUsage)) {
+      if (IOHIDElementGetType(element) == kIOHIDElementTypeInput_Button) {
+        Button button(int(buttons.Length()), element,
+                      IOHIDElementGetLogicalMin(element),
+                      IOHIDElementGetLogicalMax(element));
+        buttons.AppendElement(button);
+      } else {
+        Axis axis = {aDefaultRemapper ? int(axes.Length())
+                                      : static_cast<int>(usage - kAxisUsageMin),
+                     element,
+                     usagePage,
+                     usage,
+                     IOHIDElementGetLogicalMin(element),
+                     IOHIDElementGetLogicalMax(element)};
+        axes.AppendElement(axis);
+      }
+    } else if ((usagePage == kButtonUsagePage) ||
+               (usagePage == kConsumerPage &&
+                (usage == kHomeUsage || usage == kBackUsage))) {
+      Button button(int(buttons.Length()), element,
+                    IOHIDElementGetLogicalMin(element),
+                    IOHIDElementGetLogicalMax(element));
+      buttons.AppendElement(button);
+    } else {
+      // TODO: handle other usage pages
+    }
+  }
+}
+
+// This service is created and destroyed in Background thread while
+// operates in a seperate thread(We call it Monitor thread here).
+class DarwinGamepadService {
+ private:
+  IOHIDManagerRef mManager;
+  nsTArray<Gamepad> mGamepads;
+
+  nsCOMPtr<nsIThread> mMonitorThread;
+  nsCOMPtr<nsIThread> mBackgroundThread;
+  nsCOMPtr<nsITimer> mPollingTimer;
+  bool mIsRunning;
+
+  static void DeviceAddedCallback(void* data, IOReturn result, void* sender,
+                                  IOHIDDeviceRef device);
+  static void DeviceRemovedCallback(void* data, IOReturn result, void* sender,
+                                    IOHIDDeviceRef device);
+  static void InputValueChangedCallback(void* data, IOReturn result,
+                                        void* sender, IOHIDValueRef newValue);
+  static void EventLoopOnceCallback(nsITimer* aTimer, void* aClosure);
+
+  void DeviceAdded(IOHIDDeviceRef device);
+  void DeviceRemoved(IOHIDDeviceRef device);
+  void InputValueChanged(IOHIDValueRef value);
+  void StartupInternal();
+  void RunEventLoopOnce();
+
+ public:
+  DarwinGamepadService();
+  ~DarwinGamepadService();
+
+  static void ReportChangedCallback(void* context, IOReturn result,
+                                    void* sender, IOHIDReportType report_type,
+                                    uint32_t report_id, uint8_t* report,
+                                    CFIndex report_length);
+
+  void Startup();
+  void Shutdown();
+  void SetLightIndicatorColor(const Tainted<GamepadHandle>& aGamepadHandle,
+                              const Tainted<uint32_t>& aLightColorIndex,
+                              const uint8_t& aRed, const uint8_t& aGreen,
+                              const uint8_t& aBlue);
+  friend class DarwinGamepadServiceStartupRunnable;
+  friend class DarwinGamepadServiceShutdownRunnable;
+};
+
+class DarwinGamepadServiceStartupRunnable final : public Runnable {
+ private:
+  ~DarwinGamepadServiceStartupRunnable() {}
+  // This Runnable schedules startup of DarwinGamepadService
+  // in a new thread, pointer to DarwinGamepadService is only
+  // used by this Runnable within its thread.
+  DarwinGamepadService MOZ_NON_OWNING_REF* mService;
+
+ public:
+  explicit DarwinGamepadServiceStartupRunnable(DarwinGamepadService* service)
+      : Runnable("DarwinGamepadServiceStartupRunnable"), mService(service) {}
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT(mService);
+    mService->StartupInternal();
+    return NS_OK;
+  }
+};
+
+class DarwinGamepadServiceShutdownRunnable final : public Runnable {
+ private:
+  ~DarwinGamepadServiceShutdownRunnable() {}
+
+ public:
+  // This Runnable schedules shutdown of DarwinGamepadService
+  // in background thread.
+  explicit DarwinGamepadServiceShutdownRunnable()
+      : Runnable("DarwinGamepadServiceStartupRunnable") {}
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT(gService);
+    MOZ_ASSERT(NS_GetCurrentThread() == gService->mBackgroundThread);
+
+    IOHIDManagerRef manager = (IOHIDManagerRef)gService->mManager;
+
+    if (manager) {
+      IOHIDManagerClose(manager, 0);
+      CFRelease(manager);
+      gService->mManager = nullptr;
+    }
+    gService->mMonitorThread->Shutdown();
+    delete gService;
+    gService = nullptr;
+    return NS_OK;
+  }
+};
+
+void DarwinGamepadService::DeviceAdded(IOHIDDeviceRef device) {
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  if (!service) {
+    return;
+  }
+
+  size_t slot = size_t(-1);
+  for (size_t i = 0; i < mGamepads.Length(); i++) {
+    if (mGamepads[i] == device) return;
+    if (slot == size_t(-1) && mGamepads[i].empty()) slot = i;
+  }
+
+  if (slot == size_t(-1)) {
+    slot = mGamepads.Length();
+    mGamepads.AppendElement(Gamepad());
+  }
+
+  // Gather some identifying information
+  CFNumberRef vendorIdRef =
+      (CFNumberRef)IOHIDDeviceGetProperty(device, CFSTR(kIOHIDVendorIDKey));
+  CFNumberRef productIdRef =
+      (CFNumberRef)IOHIDDeviceGetProperty(device, CFSTR(kIOHIDProductIDKey));
+  CFStringRef productRef =
+      (CFStringRef)IOHIDDeviceGetProperty(device, CFSTR(kIOHIDProductKey));
+  int vendorId, productId;
+  CFNumberGetValue(vendorIdRef, kCFNumberIntType, &vendorId);
+  CFNumberGetValue(productIdRef, kCFNumberIntType, &productId);
+  char product_name[128];
+  CFStringGetCString(productRef, product_name, sizeof(product_name),
+                     kCFStringEncodingASCII);
+  char buffer[256];
+  SprintfLiteral(buffer, "%x-%x-%s", vendorId, productId, product_name);
+
+  bool defaultRemapper = false;
+  RefPtr<GamepadRemapper> remapper =
+      GetGamepadRemapper(vendorId, productId, defaultRemapper);
+  MOZ_ASSERT(remapper);
+  mGamepads[slot].init(device, defaultRemapper);
+
+  remapper->SetAxisCount(mGamepads[slot].numAxes());
+  remapper->SetButtonCount(mGamepads[slot].numButtons());
+
+  GamepadHandle handle = service->AddGamepad(
+      buffer, remapper->GetMappingType(), mozilla::dom::GamepadHand::_empty,
+      remapper->GetButtonCount(), remapper->GetAxisCount(),
+      0,  // TODO: Bug 680289, implement gamepad haptics for cocoa.
+      remapper->GetLightIndicatorCount(), remapper->GetTouchEventCount());
+
+  nsTArray<GamepadLightIndicatorType> lightTypes;
+  remapper->GetLightIndicators(lightTypes);
+  for (uint32_t i = 0; i < lightTypes.Length(); ++i) {
+    if (lightTypes[i] != GamepadLightIndicator::DefaultType()) {
+      service->NewLightIndicatorTypeEvent(handle, i, lightTypes[i]);
+    }
+  }
+
+  mGamepads[slot].mHandle = handle;
+  mGamepads[slot].mInputReport.SetLength(remapper->GetMaxInputReportLength());
+  mGamepads[slot].mInputReportContext = UniquePtr<GamepadInputReportContext>(
+      new GamepadInputReportContext{this, slot});
+  mGamepads[slot].mRemapper = remapper.forget();
+
+  IOHIDDeviceRegisterInputReportCallback(
+      device, mGamepads[slot].mInputReport.Elements(),
+      mGamepads[slot].mInputReport.Length(), ReportChangedCallback,
+      mGamepads[slot].mInputReportContext.get());
+}
+
+void DarwinGamepadService::DeviceRemoved(IOHIDDeviceRef device) {
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  if (!service) {
+    return;
+  }
+  for (Gamepad& gamepad : mGamepads) {
+    if (gamepad == device) {
+      IOHIDDeviceRegisterInputReportCallback(
+          device, gamepad.mInputReport.Elements(), 0, NULL,
+          gamepad.mInputReportContext.get());
+
+      gamepad.mInputReportContext.reset();
+
+      service->RemoveGamepad(gamepad.mHandle);
+      gamepad.clear();
+      return;
+    }
+  }
+}
+
+// Replace context to be Gamepad.
+void DarwinGamepadService::ReportChangedCallback(
+    void* context, IOReturn result, void* sender, IOHIDReportType report_type,
+    uint32_t report_id, uint8_t* report, CFIndex report_length) {
+  if (context && report_type == kIOHIDReportTypeInput && report_length) {
+    auto reportContext = static_cast<GamepadInputReportContext*>(context);
+    DarwinGamepadService* service = reportContext->service;
+    service->mGamepads[reportContext->gamepadSlot].ReportChanged(report,
+                                                                 report_length);
+  }
+}
+
+void Gamepad::ReportChanged(uint8_t* report, CFIndex report_len) {
+  MOZ_RELEASE_ASSERT(report_len <= mRemapper->GetMaxInputReportLength());
+  mRemapper->ProcessTouchData(mHandle, report);
+}
+
+size_t Gamepad::WriteOutputReport(const std::vector<uint8_t>& aReport) const {
+  IOReturn success =
+      IOHIDDeviceSetReport(mDevice, kIOHIDReportTypeOutput, aReport[0],
+                           aReport.data(), aReport.size());
+
+  MOZ_ASSERT(success == kIOReturnSuccess);
+  return (success == kIOReturnSuccess) ? aReport.size() : 0;
+}
+
+void DarwinGamepadService::InputValueChanged(IOHIDValueRef value) {
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  if (!service) {
+    return;
+  }
+
+  uint32_t value_length = IOHIDValueGetLength(value);
+  if (value_length > 4) {
+    // Workaround for bizarre issue with PS3 controllers that try to return
+    // massive (30+ byte) values and crash IOHIDValueGetIntegerValue
+    return;
+  }
+  IOHIDElementRef element = IOHIDValueGetElement(value);
+  IOHIDDeviceRef device = IOHIDElementGetDevice(element);
+
+  for (Gamepad& gamepad : mGamepads) {
+    if (gamepad == device) {
+      // Axis elements represent axes and d-pads.
+      if (Axis* axis = gamepad.lookupAxis(element)) {
+        const double d = IOHIDValueGetIntegerValue(value);
+        const double v =
+            2.0f * (d - axis->min) / (double)(axis->max - axis->min) - 1.0f;
+        if (axis->value != v) {
+          gamepad.mRemapper->RemapAxisMoveEvent(gamepad.mHandle, axis->id, v);
+          axis->value = v;
+        }
+      } else if (Button* button = gamepad.lookupButton(element)) {
+        const int iv = IOHIDValueGetIntegerValue(value);
+        const bool pressed = iv != 0;
+        if (button->pressed != pressed) {
+          gamepad.mRemapper->RemapButtonEvent(gamepad.mHandle, button->id,
+                                              pressed);
+          button->pressed = pressed;
+        }
+      }
+      return;
+    }
+  }
+}
+
+void DarwinGamepadService::DeviceAddedCallback(void* data, IOReturn result,
+                                               void* sender,
+                                               IOHIDDeviceRef device) {
+  DarwinGamepadService* service = (DarwinGamepadService*)data;
+  service->DeviceAdded(device);
+}
+
+void DarwinGamepadService::DeviceRemovedCallback(void* data, IOReturn result,
+                                                 void* sender,
+                                                 IOHIDDeviceRef device) {
+  DarwinGamepadService* service = (DarwinGamepadService*)data;
+  service->DeviceRemoved(device);
+}
+
+void DarwinGamepadService::InputValueChangedCallback(void* data,
+                                                     IOReturn result,
+                                                     void* sender,
+                                                     IOHIDValueRef newValue) {
+  DarwinGamepadService* service = (DarwinGamepadService*)data;
+  service->InputValueChanged(newValue);
+}
+
+void DarwinGamepadService::EventLoopOnceCallback(nsITimer* aTimer,
+                                                 void* aClosure) {
+  DarwinGamepadService* service = static_cast<DarwinGamepadService*>(aClosure);
+  service->RunEventLoopOnce();
+}
+
+static CFMutableDictionaryRef MatchingDictionary(UInt32 inUsagePage,
+                                                 UInt32 inUsage) {
+  CFMutableDictionaryRef dict = CFDictionaryCreateMutable(
+      kCFAllocatorDefault, 0, &kCFTypeDictionaryKeyCallBacks,
+      &kCFTypeDictionaryValueCallBacks);
+  if (!dict) return nullptr;
+  CFNumberRef number =
+      CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &inUsagePage);
+  if (!number) {
+    CFRelease(dict);
+    return nullptr;
+  }
+  CFDictionarySetValue(dict, CFSTR(kIOHIDDeviceUsagePageKey), number);
+  CFRelease(number);
+
+  number = CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &inUsage);
+  if (!number) {
+    CFRelease(dict);
+    return nullptr;
+  }
+  CFDictionarySetValue(dict, CFSTR(kIOHIDDeviceUsageKey), number);
+  CFRelease(number);
+
+  return dict;
+}
+
+DarwinGamepadService::DarwinGamepadService()
+    : mManager(nullptr), mIsRunning(false) {}
+
+DarwinGamepadService::~DarwinGamepadService() {
+  if (mManager != nullptr) CFRelease(mManager);
+  mMonitorThread = nullptr;
+  mBackgroundThread = nullptr;
+  if (mPollingTimer) {
+    mPollingTimer->Cancel();
+    mPollingTimer = nullptr;
+  }
+}
+
+void DarwinGamepadService::RunEventLoopOnce() {
+  MOZ_ASSERT(NS_GetCurrentThread() == mMonitorThread);
+  CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0.0, true);
+
+  // This timer must be created in monitor thread
+  if (!mPollingTimer) {
+    mPollingTimer = NS_NewTimer();
+  }
+  mPollingTimer->Cancel();
+  if (mIsRunning) {
+    mPollingTimer->InitWithNamedFuncCallback(
+        EventLoopOnceCallback, this, kDarwinGamepadPollInterval,
+        nsITimer::TYPE_ONE_SHOT, "EventLoopOnceCallback");
+  } else {
+    // We schedule a task shutdown and cleaning up resources to Background
+    // thread here to make sure no runloop is running to prevent potential race
+    // condition.
+    RefPtr<Runnable> shutdownTask = new DarwinGamepadServiceShutdownRunnable();
+    mBackgroundThread->Dispatch(shutdownTask.forget(), NS_DISPATCH_NORMAL);
+  }
+}
+
+void DarwinGamepadService::StartupInternal() {
+  if (mManager != nullptr) return;
+
+  IOHIDManagerRef manager =
+      IOHIDManagerCreate(kCFAllocatorDefault, kIOHIDOptionsTypeNone);
+
+  CFMutableDictionaryRef criteria_arr[2];
+  criteria_arr[0] = MatchingDictionary(kDesktopUsagePage, kJoystickUsage);
+  if (!criteria_arr[0]) {
+    CFRelease(manager);
+    return;
+  }
+
+  criteria_arr[1] = MatchingDictionary(kDesktopUsagePage, kGamepadUsage);
+  if (!criteria_arr[1]) {
+    CFRelease(criteria_arr[0]);
+    CFRelease(manager);
+    return;
+  }
+
+  CFArrayRef criteria = CFArrayCreate(kCFAllocatorDefault,
+                                      (const void**)criteria_arr, 2, nullptr);
+  if (!criteria) {
+    CFRelease(criteria_arr[1]);
+    CFRelease(criteria_arr[0]);
+    CFRelease(manager);
+    return;
+  }
+
+  IOHIDManagerSetDeviceMatchingMultiple(manager, criteria);
+  CFRelease(criteria);
+  CFRelease(criteria_arr[1]);
+  CFRelease(criteria_arr[0]);
+
+  IOHIDManagerRegisterDeviceMatchingCallback(manager, DeviceAddedCallback,
+                                             this);
+  IOHIDManagerRegisterDeviceRemovalCallback(manager, DeviceRemovedCallback,
+                                            this);
+  IOHIDManagerRegisterInputValueCallback(manager, InputValueChangedCallback,
+                                         this);
+  IOHIDManagerScheduleWithRunLoop(manager, CFRunLoopGetCurrent(),
+                                  kCFRunLoopDefaultMode);
+  IOReturn rv = IOHIDManagerOpen(manager, kIOHIDOptionsTypeNone);
+  if (rv != kIOReturnSuccess) {
+    CFRelease(manager);
+    return;
+  }
+
+  mManager = manager;
+
+  mIsRunning = true;
+  RunEventLoopOnce();
+}
+
+void DarwinGamepadService::Startup() {
+  mBackgroundThread = NS_GetCurrentThread();
+  Unused << NS_NewNamedThread("Gamepad", getter_AddRefs(mMonitorThread),
+                              new DarwinGamepadServiceStartupRunnable(this));
+}
+
+void DarwinGamepadService::Shutdown() {
+  // Flipping this flag will stop the eventloop in Monitor thread
+  // and dispatch a task destroying and cleaning up resources in
+  // Background thread
+  mIsRunning = false;
+}
+
+void DarwinGamepadService::SetLightIndicatorColor(
+    const Tainted<GamepadHandle>& aGamepadHandle,
+    const Tainted<uint32_t>& aLightColorIndex, const uint8_t& aRed,
+    const uint8_t& aGreen, const uint8_t& aBlue) {
+  // We get aControllerIdx from GamepadPlatformService::AddGamepad(),
+  // It begins from 1 and is stored at Gamepad.id.
+  const Gamepad* gamepad = MOZ_FIND_AND_VALIDATE(
+      aGamepadHandle, list_item.mHandle == aGamepadHandle, mGamepads);
+  if (!gamepad) {
+    MOZ_ASSERT(false);
+    return;
+  }
+
+  RefPtr<GamepadRemapper> remapper = gamepad->mRemapper;
+  if (!remapper ||
+      MOZ_IS_VALID(aLightColorIndex,
+                   remapper->GetLightIndicatorCount() <= aLightColorIndex)) {
+    MOZ_ASSERT(false);
+    return;
+  }
+
+  std::vector<uint8_t> report;
+  remapper->GetLightColorReport(aRed, aGreen, aBlue, report);
+  gamepad->WriteOutputReport(report);
+}
+
+}  // namespace
+
+namespace mozilla {
+namespace dom {
+
+void StartGamepadMonitoring() {
+  ::mozilla::ipc::AssertIsOnBackgroundThread();
+  if (gService) {
+    return;
+  }
+
+  gService = new DarwinGamepadService();
+  gService->Startup();
+}
+
+void StopGamepadMonitoring() {
+  ::mozilla::ipc::AssertIsOnBackgroundThread();
+  if (!gService) {
+    return;
+  }
+
+  // Calling Shutdown() will delete gService as well
+  gService->Shutdown();
+}
+
+void SetGamepadLightIndicatorColor(const Tainted<GamepadHandle>& aGamepadHandle,
+                                   const Tainted<uint32_t>& aLightColorIndex,
+                                   const uint8_t& aRed, const uint8_t& aGreen,
+                                   const uint8_t& aBlue) {
+  MOZ_ASSERT(gService);
+  if (!gService) {
+    return;
+  }
+  gService->SetLightIndicatorColor(aGamepadHandle, aLightColorIndex, aRed,
+                                   aGreen, aBlue);
+}
+
+}  // namespace dom
+}  // namespace mozilla
diff --git a/dom/gamepad/fallback/FallbackGamepad.cpp b/dom/gamepad/fallback/FallbackGamepad.cpp
new file mode 100644
index 0000000000..4b37732f51
--- /dev/null
+++ b/dom/gamepad/fallback/FallbackGamepad.cpp
@@ -0,0 +1,22 @@
+/* -*- 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 <stdint.h>
+#include "mozilla/dom/GamepadHandle.h"
+
+namespace mozilla {
+namespace dom {
+
+void StartGamepadMonitoring() {}
+
+void StopGamepadMonitoring() {}
+
+void SetGamepadLightIndicatorColor(const Tainted<GamepadHandle>&,
+                                   const Tainted<uint32_t>&, const uint8_t&,
+                                   const uint8_t&, const uint8_t&) {}
+
+}  // namespace dom
+}  // namespace mozilla
diff --git a/dom/gamepad/ipc/GamepadEventChannelChild.cpp b/dom/gamepad/ipc/GamepadEventChannelChild.cpp
new file mode 100644
index 0000000000..ef8528f565
--- /dev/null
+++ b/dom/gamepad/ipc/GamepadEventChannelChild.cpp
@@ -0,0 +1,63 @@
+/* -*- 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 "GamepadEventChannelChild.h"
+#include "mozilla/dom/GamepadManager.h"
+#include "mozilla/dom/Promise.h"
+
+namespace mozilla::dom {
+
+namespace {
+
+class GamepadUpdateRunnable final : public Runnable {
+ public:
+  explicit GamepadUpdateRunnable(const GamepadChangeEvent& aGamepadEvent)
+      : Runnable("dom::GamepadUpdateRunnable"), mEvent(aGamepadEvent) {}
+  NS_IMETHOD Run() override {
+    RefPtr<GamepadManager> svc(GamepadManager::GetService());
+    if (svc) {
+      svc->Update(mEvent);
+    }
+    return NS_OK;
+  }
+
+ protected:
+  GamepadChangeEvent mEvent;
+};
+
+}  // namespace
+
+already_AddRefed<GamepadEventChannelChild> GamepadEventChannelChild::Create() {
+  return RefPtr<GamepadEventChannelChild>(new GamepadEventChannelChild())
+      .forget();
+}
+
+mozilla::ipc::IPCResult GamepadEventChannelChild::RecvGamepadUpdate(
+    const GamepadChangeEvent& aGamepadEvent) {
+  DebugOnly<nsresult> rv =
+      NS_DispatchToMainThread(new GamepadUpdateRunnable(aGamepadEvent));
+  NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "NS_DispatchToMainThread failed");
+  return IPC_OK();
+}
+
+void GamepadEventChannelChild::AddPromise(const uint32_t& aID,
+                                          dom::Promise* aPromise) {
+  MOZ_ASSERT(!mPromiseList.Contains(aID));
+  mPromiseList.InsertOrUpdate(aID, RefPtr{aPromise});
+}
+
+mozilla::ipc::IPCResult GamepadEventChannelChild::RecvReplyGamepadPromise(
+    const uint32_t& aPromiseID) {
+  RefPtr<dom::Promise> p;
+  if (!mPromiseList.Get(aPromiseID, getter_AddRefs(p))) {
+    MOZ_CRASH("We should always have a promise.");
+  }
+
+  p->MaybeResolve(true);
+  mPromiseList.Remove(aPromiseID);
+  return IPC_OK();
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/ipc/GamepadEventChannelChild.h b/dom/gamepad/ipc/GamepadEventChannelChild.h
new file mode 100644
index 0000000000..97fd0576a4
--- /dev/null
+++ b/dom/gamepad/ipc/GamepadEventChannelChild.h
@@ -0,0 +1,39 @@
+/* -*- 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 "mozilla/dom/PGamepadEventChannelChild.h"
+#include "nsRefPtrHashtable.h"
+
+#ifndef mozilla_dom_GamepadEventChannelChild_h_
+#  define mozilla_dom_GamepadEventChannelChild_h_
+
+namespace mozilla::dom {
+
+class GamepadEventChannelChild final : public PGamepadEventChannelChild {
+ public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(GamepadEventChannelChild, override)
+
+  static already_AddRefed<GamepadEventChannelChild> Create();
+
+  mozilla::ipc::IPCResult RecvGamepadUpdate(
+      const GamepadChangeEvent& aGamepadEvent);
+  mozilla::ipc::IPCResult RecvReplyGamepadPromise(const uint32_t& aPromiseID);
+  void AddPromise(const uint32_t& aID, dom::Promise* aPromise);
+
+  GamepadEventChannelChild(const GamepadEventChannelChild&) = delete;
+  GamepadEventChannelChild(GamepadEventChannelChild&&) = delete;
+  GamepadEventChannelChild& operator=(const GamepadEventChannelChild&) = delete;
+  GamepadEventChannelChild& operator=(GamepadEventChannelChild&&) = delete;
+
+ private:
+  GamepadEventChannelChild() = default;
+  ~GamepadEventChannelChild() = default;
+
+  nsRefPtrHashtable<nsUint32HashKey, dom::Promise> mPromiseList;
+};
+
+}  // namespace mozilla::dom
+
+#endif
diff --git a/dom/gamepad/ipc/GamepadEventChannelParent.cpp b/dom/gamepad/ipc/GamepadEventChannelParent.cpp
new file mode 100644
index 0000000000..4a21948c06
--- /dev/null
+++ b/dom/gamepad/ipc/GamepadEventChannelParent.cpp
@@ -0,0 +1,109 @@
+/* -*- 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 "GamepadEventChannelParent.h"
+#include "GamepadPlatformService.h"
+#include "mozilla/dom/GamepadMonitoring.h"
+#include "mozilla/ipc/BackgroundParent.h"
+#include "nsThreadUtils.h"
+
+namespace mozilla::dom {
+
+using namespace mozilla::ipc;
+
+namespace {
+
+class SendGamepadUpdateRunnable final : public Runnable {
+ private:
+  ~SendGamepadUpdateRunnable() = default;
+  RefPtr<GamepadEventChannelParent> mParent;
+  GamepadChangeEvent mEvent;
+
+ public:
+  SendGamepadUpdateRunnable(GamepadEventChannelParent* aParent,
+                            GamepadChangeEvent aEvent)
+      : Runnable("dom::SendGamepadUpdateRunnable"),
+        mParent(aParent),
+        mEvent(aEvent) {
+    MOZ_ASSERT(mParent);
+  }
+  NS_IMETHOD Run() override {
+    AssertIsOnBackgroundThread();
+    Unused << mParent->SendGamepadUpdate(mEvent);
+    return NS_OK;
+  }
+};
+
+}  // namespace
+
+already_AddRefed<GamepadEventChannelParent>
+GamepadEventChannelParent::Create() {
+  return RefPtr<GamepadEventChannelParent>(new GamepadEventChannelParent())
+      .forget();
+}
+
+GamepadEventChannelParent::GamepadEventChannelParent() : mIsShutdown{false} {
+  MOZ_DIAGNOSTIC_ASSERT(IsOnBackgroundThread());
+
+  mBackgroundEventTarget = GetCurrentSerialEventTarget();
+
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  MOZ_ASSERT(service);
+
+  service->AddChannelParent(this);
+}
+
+void GamepadEventChannelParent::ActorDestroy(ActorDestroyReason aWhy) {
+  MOZ_DIAGNOSTIC_ASSERT(IsOnBackgroundThread());
+  MOZ_DIAGNOSTIC_ASSERT(!mIsShutdown);
+
+  mIsShutdown = true;
+
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  MOZ_ASSERT(service);
+  service->RemoveChannelParent(this);
+}
+
+mozilla::ipc::IPCResult GamepadEventChannelParent::RecvVibrateHaptic(
+    const Tainted<GamepadHandle>& aHandle,
+    const Tainted<uint32_t>& aHapticIndex, const Tainted<double>& aIntensity,
+    const Tainted<double>& aDuration, const uint32_t& aPromiseID) {
+  // TODO: Bug 680289, implement for standard gamepads
+
+  if (SendReplyGamepadPromise(aPromiseID)) {
+    return IPC_OK();
+  }
+
+  return IPC_FAIL(this, "SendReplyGamepadPromise fail.");
+}
+
+mozilla::ipc::IPCResult GamepadEventChannelParent::RecvStopVibrateHaptic(
+    const Tainted<GamepadHandle>& aHandle) {
+  // TODO: Bug 680289, implement for standard gamepads
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult GamepadEventChannelParent::RecvLightIndicatorColor(
+    const Tainted<GamepadHandle>& aHandle,
+    const Tainted<uint32_t>& aLightColorIndex, const uint8_t& aRed,
+    const uint8_t& aGreen, const uint8_t& aBlue, const uint32_t& aPromiseID) {
+  SetGamepadLightIndicatorColor(aHandle, aLightColorIndex, aRed, aGreen, aBlue);
+
+  if (SendReplyGamepadPromise(aPromiseID)) {
+    return IPC_OK();
+  }
+
+  return IPC_FAIL(this, "SendReplyGamepadPromise fail.");
+}
+
+void GamepadEventChannelParent::DispatchUpdateEvent(
+    const GamepadChangeEvent& aEvent) {
+  mBackgroundEventTarget->Dispatch(new SendGamepadUpdateRunnable(this, aEvent),
+                                   NS_DISPATCH_NORMAL);
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/ipc/GamepadEventChannelParent.h b/dom/gamepad/ipc/GamepadEventChannelParent.h
new file mode 100644
index 0000000000..90bb7e7f4d
--- /dev/null
+++ b/dom/gamepad/ipc/GamepadEventChannelParent.h
@@ -0,0 +1,48 @@
+/* -*- 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 "mozilla/dom/PGamepadEventChannelParent.h"
+
+#ifndef mozilla_dom_GamepadEventChannelParent_h_
+#  define mozilla_dom_GamepadEventChannelParent_h_
+
+namespace mozilla::dom {
+
+class GamepadEventChannelParent final : public PGamepadEventChannelParent {
+ public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(GamepadEventChannelParent, override)
+
+  static already_AddRefed<GamepadEventChannelParent> Create();
+  void ActorDestroy(ActorDestroyReason aWhy) override;
+
+  mozilla::ipc::IPCResult RecvVibrateHaptic(
+      const Tainted<GamepadHandle>& aHandle,
+      const Tainted<uint32_t>& aHapticIndex, const Tainted<double>& aIntensity,
+      const Tainted<double>& aDuration, const uint32_t& aPromiseID);
+  mozilla::ipc::IPCResult RecvStopVibrateHaptic(
+      const Tainted<GamepadHandle>& aHandle);
+  mozilla::ipc::IPCResult RecvLightIndicatorColor(
+      const Tainted<GamepadHandle>& aHandle,
+      const Tainted<uint32_t>& aLightColorIndex, const uint8_t& aRed,
+      const uint8_t& aGreen, const uint8_t& aBlue, const uint32_t& aPromiseID);
+  void DispatchUpdateEvent(const GamepadChangeEvent& aEvent);
+
+  GamepadEventChannelParent(const GamepadEventChannelParent&) = delete;
+  GamepadEventChannelParent(GamepadEventChannelParent&&) = delete;
+  GamepadEventChannelParent& operator=(const GamepadEventChannelParent&) =
+      delete;
+  GamepadEventChannelParent& operator=(GamepadEventChannelParent&&) = delete;
+
+ private:
+  GamepadEventChannelParent();
+  ~GamepadEventChannelParent() = default;
+
+  bool mIsShutdown;
+  nsCOMPtr<nsIEventTarget> mBackgroundEventTarget;
+};
+
+}  // namespace mozilla::dom
+
+#endif
diff --git a/dom/gamepad/ipc/GamepadEventTypes.ipdlh b/dom/gamepad/ipc/GamepadEventTypes.ipdlh
new file mode 100644
index 0000000000..4ac1d7dc93
--- /dev/null
+++ b/dom/gamepad/ipc/GamepadEventTypes.ipdlh
@@ -0,0 +1,78 @@
+/* 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 "mozilla/dom/GamepadMessageUtils.h";
+
+using mozilla::dom::GamepadPoseState from "mozilla/dom/GamepadPoseState.h";
+using mozilla::dom::GamepadTouchState from "mozilla/dom/GamepadTouchState.h";
+using mozilla::dom::GamepadLightIndicatorType from "mozilla/dom/GamepadLightIndicatorBinding.h";
+using mozilla::dom::GamepadMappingType from "mozilla/dom/GamepadBinding.h";
+using mozilla::dom::GamepadHand from "mozilla/dom/GamepadBinding.h";
+using mozilla::dom::GamepadHandle from "mozilla/dom/GamepadHandle.h";
+
+namespace mozilla {
+namespace dom {
+
+struct GamepadAdded {
+  nsString id;
+  GamepadMappingType mapping;
+  GamepadHand hand;
+  uint32_t display_id;
+  uint32_t num_buttons;
+  uint32_t num_axes;
+  uint32_t num_haptics;
+  uint32_t num_lights;
+  uint32_t num_touches;
+};
+
+struct GamepadRemoved {};
+
+struct GamepadAxisInformation {
+  uint32_t axis;
+  double value;
+};
+
+struct GamepadButtonInformation {
+  uint32_t button;
+  double value;
+  bool pressed;
+  bool touched;
+};
+
+struct GamepadPoseInformation {
+  GamepadPoseState pose_state;
+};
+
+struct GamepadLightIndicatorTypeInformation {
+  uint32_t light;
+  GamepadLightIndicatorType type;
+};
+
+struct GamepadHandInformation {
+  GamepadHand hand;
+};
+
+struct GamepadTouchInformation {
+  uint32_t index;
+  GamepadTouchState touch_state;
+};
+
+union GamepadChangeEventBody {
+  GamepadAdded;
+  GamepadRemoved;
+  GamepadAxisInformation;
+  GamepadButtonInformation;
+  GamepadHandInformation;
+  GamepadLightIndicatorTypeInformation;
+  GamepadPoseInformation;
+  GamepadTouchInformation;
+};
+
+struct GamepadChangeEvent {
+  GamepadHandle handle;
+  GamepadChangeEventBody body;
+};
+
+} // namespace dom
+} // namespace mozilla
\ No newline at end of file
diff --git a/dom/gamepad/ipc/GamepadMessageUtils.h b/dom/gamepad/ipc/GamepadMessageUtils.h
new file mode 100644
index 0000000000..c29293d3a5
--- /dev/null
+++ b/dom/gamepad/ipc/GamepadMessageUtils.h
@@ -0,0 +1,154 @@
+/* -*- 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_gamepad_GamepadMessageUtils_h
+#define mozilla_dom_gamepad_GamepadMessageUtils_h
+
+#include "ipc/EnumSerializer.h"
+#include "mozilla/dom/GamepadBinding.h"
+#include "mozilla/dom/GamepadHandle.h"
+#include "mozilla/dom/GamepadLightIndicatorBinding.h"
+#include "mozilla/dom/GamepadPoseState.h"
+#include "mozilla/dom/GamepadTouchState.h"
+
+namespace IPC {
+
+template <>
+struct ParamTraits<mozilla::dom::GamepadLightIndicatorType>
+    : public ContiguousEnumSerializer<
+          mozilla::dom::GamepadLightIndicatorType,
+          mozilla::dom::GamepadLightIndicatorType(0),
+          mozilla::dom::GamepadLightIndicatorType(
+              mozilla::dom::GamepadLightIndicatorType::EndGuard_)> {};
+
+template <>
+struct ParamTraits<mozilla::dom::GamepadMappingType>
+    : public ContiguousEnumSerializer<
+          mozilla::dom::GamepadMappingType, mozilla::dom::GamepadMappingType(0),
+          mozilla::dom::GamepadMappingType(
+              mozilla::dom::GamepadMappingType::EndGuard_)> {};
+
+template <>
+struct ParamTraits<mozilla::dom::GamepadHand>
+    : public ContiguousEnumSerializer<
+          mozilla::dom::GamepadHand, mozilla::dom::GamepadHand(0),
+          mozilla::dom::GamepadHand(mozilla::dom::GamepadHand::EndGuard_)> {};
+
+template <>
+struct ParamTraits<mozilla::dom::GamepadCapabilityFlags>
+    : public BitFlagsEnumSerializer<
+          mozilla::dom::GamepadCapabilityFlags,
+          mozilla::dom::GamepadCapabilityFlags::Cap_All> {};
+
+template <>
+struct ParamTraits<mozilla::dom::GamepadPoseState> {
+  typedef mozilla::dom::GamepadPoseState paramType;
+
+  static void Write(MessageWriter* aWriter, const paramType& aParam) {
+    WriteParam(aWriter, aParam.flags);
+    WriteParam(aWriter, aParam.orientation[0]);
+    WriteParam(aWriter, aParam.orientation[1]);
+    WriteParam(aWriter, aParam.orientation[2]);
+    WriteParam(aWriter, aParam.orientation[3]);
+    WriteParam(aWriter, aParam.position[0]);
+    WriteParam(aWriter, aParam.position[1]);
+    WriteParam(aWriter, aParam.position[2]);
+    WriteParam(aWriter, aParam.angularVelocity[0]);
+    WriteParam(aWriter, aParam.angularVelocity[1]);
+    WriteParam(aWriter, aParam.angularVelocity[2]);
+    WriteParam(aWriter, aParam.angularAcceleration[0]);
+    WriteParam(aWriter, aParam.angularAcceleration[1]);
+    WriteParam(aWriter, aParam.angularAcceleration[2]);
+    WriteParam(aWriter, aParam.linearVelocity[0]);
+    WriteParam(aWriter, aParam.linearVelocity[1]);
+    WriteParam(aWriter, aParam.linearVelocity[2]);
+    WriteParam(aWriter, aParam.linearAcceleration[0]);
+    WriteParam(aWriter, aParam.linearAcceleration[1]);
+    WriteParam(aWriter, aParam.linearAcceleration[2]);
+    WriteParam(aWriter, aParam.isPositionValid);
+    WriteParam(aWriter, aParam.isOrientationValid);
+  }
+
+  static bool Read(MessageReader* aReader, paramType* aResult) {
+    if (!ReadParam(aReader, &(aResult->flags)) ||
+        !ReadParam(aReader, &(aResult->orientation[0])) ||
+        !ReadParam(aReader, &(aResult->orientation[1])) ||
+        !ReadParam(aReader, &(aResult->orientation[2])) ||
+        !ReadParam(aReader, &(aResult->orientation[3])) ||
+        !ReadParam(aReader, &(aResult->position[0])) ||
+        !ReadParam(aReader, &(aResult->position[1])) ||
+        !ReadParam(aReader, &(aResult->position[2])) ||
+        !ReadParam(aReader, &(aResult->angularVelocity[0])) ||
+        !ReadParam(aReader, &(aResult->angularVelocity[1])) ||
+        !ReadParam(aReader, &(aResult->angularVelocity[2])) ||
+        !ReadParam(aReader, &(aResult->angularAcceleration[0])) ||
+        !ReadParam(aReader, &(aResult->angularAcceleration[1])) ||
+        !ReadParam(aReader, &(aResult->angularAcceleration[2])) ||
+        !ReadParam(aReader, &(aResult->linearVelocity[0])) ||
+        !ReadParam(aReader, &(aResult->linearVelocity[1])) ||
+        !ReadParam(aReader, &(aResult->linearVelocity[2])) ||
+        !ReadParam(aReader, &(aResult->linearAcceleration[0])) ||
+        !ReadParam(aReader, &(aResult->linearAcceleration[1])) ||
+        !ReadParam(aReader, &(aResult->linearAcceleration[2])) ||
+        !ReadParam(aReader, &(aResult->isPositionValid)) ||
+        !ReadParam(aReader, &(aResult->isOrientationValid))) {
+      return false;
+    }
+    return true;
+  }
+};
+
+template <>
+struct ParamTraits<mozilla::dom::GamepadTouchState> {
+  typedef mozilla::dom::GamepadTouchState paramType;
+
+  static void Write(MessageWriter* aWriter, const paramType& aParam) {
+    WriteParam(aWriter, aParam.touchId);
+    WriteParam(aWriter, aParam.surfaceId);
+    WriteParam(aWriter, aParam.position[0]);
+    WriteParam(aWriter, aParam.position[1]);
+    WriteParam(aWriter, aParam.surfaceDimensions[0]);
+    WriteParam(aWriter, aParam.surfaceDimensions[1]);
+    WriteParam(aWriter, aParam.isSurfaceDimensionsValid);
+  }
+
+  static bool Read(MessageReader* aReader, paramType* aResult) {
+    if (!ReadParam(aReader, &(aResult->touchId)) ||
+        !ReadParam(aReader, &(aResult->surfaceId)) ||
+        !ReadParam(aReader, &(aResult->position[0])) ||
+        !ReadParam(aReader, &(aResult->position[1])) ||
+        !ReadParam(aReader, &(aResult->surfaceDimensions[0])) ||
+        !ReadParam(aReader, &(aResult->surfaceDimensions[1])) ||
+        !ReadParam(aReader, &(aResult->isSurfaceDimensionsValid))) {
+      return false;
+    }
+    return true;
+  }
+};
+
+template <>
+struct ParamTraits<mozilla::dom::GamepadHandleKind>
+    : public ContiguousEnumSerializerInclusive<
+          mozilla::dom::GamepadHandleKind,
+          mozilla::dom::GamepadHandleKind::GamepadPlatformManager,
+          mozilla::dom::GamepadHandleKind::VR> {};
+
+template <>
+struct ParamTraits<mozilla::dom::GamepadHandle> {
+  typedef mozilla::dom::GamepadHandle paramType;
+  static void Write(MessageWriter* aWriter, const paramType& aParam) {
+    WriteParam(aWriter, aParam.mValue);
+    WriteParam(aWriter, aParam.mKind);
+  }
+  static bool Read(MessageReader* aReader, paramType* aParam) {
+    return ReadParam(aReader, &aParam->mValue) &&
+           ReadParam(aReader, &aParam->mKind);
+  }
+};
+
+}  // namespace IPC
+
+#endif  // mozilla_dom_gamepad_GamepadMessageUtils_h
diff --git a/dom/gamepad/ipc/GamepadTestChannelChild.cpp b/dom/gamepad/ipc/GamepadTestChannelChild.cpp
new file mode 100644
index 0000000000..d74e0736ce
--- /dev/null
+++ b/dom/gamepad/ipc/GamepadTestChannelChild.cpp
@@ -0,0 +1,34 @@
+/* -*- 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 "GamepadTestChannelChild.h"
+
+#include "mozilla/dom/GamepadServiceTest.h"
+
+namespace mozilla::dom {
+
+already_AddRefed<GamepadTestChannelChild> GamepadTestChannelChild::Create(
+    GamepadServiceTest* aGamepadServiceTest) {
+  return RefPtr<GamepadTestChannelChild>(
+             new GamepadTestChannelChild(aGamepadServiceTest))
+      .forget();
+}
+
+GamepadTestChannelChild::GamepadTestChannelChild(
+    GamepadServiceTest* aGamepadServiceTest)
+    : mGamepadServiceTest(aGamepadServiceTest) {}
+
+mozilla::ipc::IPCResult GamepadTestChannelChild::RecvReplyGamepadHandle(
+    const uint32_t& aID, const GamepadHandle& aHandle) {
+  MOZ_RELEASE_ASSERT(
+      mGamepadServiceTest,
+      "Test channel should never outlive the owning GamepadServiceTest");
+
+  mGamepadServiceTest->ReplyGamepadHandle(aID, aHandle);
+  return IPC_OK();
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/ipc/GamepadTestChannelChild.h b/dom/gamepad/ipc/GamepadTestChannelChild.h
new file mode 100644
index 0000000000..26d499ff8a
--- /dev/null
+++ b/dom/gamepad/ipc/GamepadTestChannelChild.h
@@ -0,0 +1,45 @@
+/* -*- 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_GamepadTestChannelChild_h_
+#define mozilla_dom_GamepadTestChannelChild_h_
+
+#include "mozilla/dom/PGamepadTestChannelChild.h"
+#include "mozilla/dom/Promise.h"
+#include "mozilla/WeakPtr.h"
+#include "nsRefPtrHashtable.h"
+
+namespace mozilla::dom {
+
+class GamepadServiceTest;
+
+class GamepadTestChannelChild final : public PGamepadTestChannelChild {
+ public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(GamepadTestChannelChild)
+
+  static already_AddRefed<GamepadTestChannelChild> Create(
+      GamepadServiceTest* aGamepadServiceTest);
+
+  GamepadTestChannelChild(const GamepadTestChannelChild&) = delete;
+  GamepadTestChannelChild(GamepadTestChannelChild&&) = delete;
+  GamepadTestChannelChild& operator=(const GamepadTestChannelChild&) = delete;
+  GamepadTestChannelChild& operator=(GamepadTestChannelChild&&) = delete;
+
+ private:
+  explicit GamepadTestChannelChild(GamepadServiceTest* aGamepadServiceTest);
+  ~GamepadTestChannelChild() = default;
+
+  mozilla::ipc::IPCResult RecvReplyGamepadHandle(const uint32_t& aID,
+                                                 const GamepadHandle& aHandle);
+
+  WeakPtr<GamepadServiceTest> mGamepadServiceTest;
+
+  friend class PGamepadTestChannelChild;
+};
+
+}  // namespace mozilla::dom
+
+#endif
diff --git a/dom/gamepad/ipc/GamepadTestChannelParent.cpp b/dom/gamepad/ipc/GamepadTestChannelParent.cpp
new file mode 100644
index 0000000000..1c8d67491e
--- /dev/null
+++ b/dom/gamepad/ipc/GamepadTestChannelParent.cpp
@@ -0,0 +1,129 @@
+/* -*- 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 "GamepadTestChannelParent.h"
+
+#include "mozilla/dom/GamepadPlatformService.h"
+#include "mozilla/ipc/BackgroundParent.h"
+#include "mozilla/StaticPrefs_dom.h"
+#include "mozilla/Unused.h"
+
+namespace mozilla::dom {
+
+already_AddRefed<GamepadTestChannelParent> GamepadTestChannelParent::Create() {
+  // Refuse to create the parent actor if this pref is disabled
+  if (!StaticPrefs::dom_gamepad_test_enabled()) {
+    return nullptr;
+  }
+
+  return RefPtr<GamepadTestChannelParent>(new GamepadTestChannelParent())
+      .forget();
+}
+
+GamepadTestChannelParent::GamepadTestChannelParent() {
+  ::mozilla::ipc::AssertIsOnBackgroundThread();
+  GamepadMonitoringState::GetSingleton().AddObserver(this);
+}
+
+GamepadTestChannelParent::~GamepadTestChannelParent() {
+  ::mozilla::ipc::AssertIsOnBackgroundThread();
+  GamepadMonitoringState::GetSingleton().RemoveObserver(this);
+}
+
+void GamepadTestChannelParent::AddGamepadToPlatformService(
+    uint32_t aPromiseId, const GamepadAdded& aGamepadAdded) {
+  mozilla::ipc::AssertIsOnBackgroundThread();
+
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  MOZ_ASSERT(service);
+
+  const GamepadAdded& a = aGamepadAdded;
+  nsCString gamepadID;
+  LossyCopyUTF16toASCII(a.id(), gamepadID);
+  GamepadHandle handle = service->AddGamepad(
+      gamepadID.get(), static_cast<GamepadMappingType>(a.mapping()), a.hand(),
+      a.num_buttons(), a.num_axes(), a.num_haptics(), a.num_lights(),
+      a.num_touches());
+
+  Unused << SendReplyGamepadHandle(aPromiseId, handle);
+}
+
+void GamepadTestChannelParent::OnMonitoringStateChanged(bool aNewState) {
+  mozilla::ipc::AssertIsOnBackgroundThread();
+
+  if (aNewState) {
+    for (auto& deferredGamepadAdd : mDeferredGamepadAdded) {
+      AddGamepadToPlatformService(deferredGamepadAdd.promiseId,
+                                  deferredGamepadAdd.gamepadAdded);
+    }
+    mDeferredGamepadAdded.Clear();
+  }
+}
+
+mozilla::ipc::IPCResult GamepadTestChannelParent::RecvGamepadTestEvent(
+    const uint32_t& aID, const GamepadChangeEvent& aEvent) {
+  mozilla::ipc::AssertIsOnBackgroundThread();
+
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  MOZ_ASSERT(service);
+
+  const GamepadChangeEventBody& body = aEvent.body();
+
+  // GamepadAdded is special because it will be deferred if monitoring hasn't
+  // started. Everything else won't be deferred and will fail if monitoring
+  // isn't running
+  if (body.type() == GamepadChangeEventBody::TGamepadAdded) {
+    if (GamepadMonitoringState::GetSingleton().IsMonitoring()) {
+      AddGamepadToPlatformService(aID, body.get_GamepadAdded());
+    } else {
+      mDeferredGamepadAdded.AppendElement(
+          DeferredGamepadAdded{aID, body.get_GamepadAdded()});
+    }
+    return IPC_OK();
+  }
+
+  if (!GamepadMonitoringState::GetSingleton().IsMonitoring()) {
+    return IPC_FAIL(this, "Simulated message received while not monitoring");
+  }
+
+  GamepadHandle handle = aEvent.handle();
+
+  switch (body.type()) {
+    case GamepadChangeEventBody::TGamepadRemoved:
+      service->RemoveGamepad(handle);
+      break;
+    case GamepadChangeEventBody::TGamepadButtonInformation: {
+      const GamepadButtonInformation& a = body.get_GamepadButtonInformation();
+      service->NewButtonEvent(handle, a.button(), a.pressed(), a.touched(),
+                              a.value());
+      break;
+    }
+    case GamepadChangeEventBody::TGamepadAxisInformation: {
+      const GamepadAxisInformation& a = body.get_GamepadAxisInformation();
+      service->NewAxisMoveEvent(handle, a.axis(), a.value());
+      break;
+    }
+    case GamepadChangeEventBody::TGamepadPoseInformation: {
+      const GamepadPoseInformation& a = body.get_GamepadPoseInformation();
+      service->NewPoseEvent(handle, a.pose_state());
+      break;
+    }
+    case GamepadChangeEventBody::TGamepadTouchInformation: {
+      const GamepadTouchInformation& a = body.get_GamepadTouchInformation();
+      service->NewMultiTouchEvent(handle, a.index(), a.touch_state());
+      break;
+    }
+    default:
+      NS_WARNING("Unknown event type.");
+      return IPC_FAIL_NO_REASON(this);
+  }
+  Unused << SendReplyGamepadHandle(aID, handle);
+  return IPC_OK();
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/ipc/GamepadTestChannelParent.h b/dom/gamepad/ipc/GamepadTestChannelParent.h
new file mode 100644
index 0000000000..03567727e2
--- /dev/null
+++ b/dom/gamepad/ipc/GamepadTestChannelParent.h
@@ -0,0 +1,49 @@
+/* -*- 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 "mozilla/dom/PGamepadTestChannelParent.h"
+#include "mozilla/WeakPtr.h"
+
+#ifndef mozilla_dom_GamepadTestChannelParent_h_
+#  define mozilla_dom_GamepadTestChannelParent_h_
+
+namespace mozilla::dom {
+
+class GamepadTestChannelParent final : public PGamepadTestChannelParent,
+                                       public SupportsWeakPtr {
+ public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(GamepadTestChannelParent)
+
+  static already_AddRefed<GamepadTestChannelParent> Create();
+
+  mozilla::ipc::IPCResult RecvGamepadTestEvent(
+      const uint32_t& aID, const GamepadChangeEvent& aGamepadEvent);
+
+  void OnMonitoringStateChanged(bool aNewState);
+
+  GamepadTestChannelParent(const GamepadTestChannelParent&) = delete;
+  GamepadTestChannelParent(GamepadTestChannelParent&&) = delete;
+  GamepadTestChannelParent& operator=(const GamepadTestChannelParent&) = delete;
+  GamepadTestChannelParent& operator=(GamepadTestChannelParent&&) = delete;
+
+ private:
+  struct DeferredGamepadAdded {
+    uint32_t promiseId;
+    GamepadAdded gamepadAdded;
+  };
+
+  GamepadTestChannelParent();
+  ~GamepadTestChannelParent();
+
+  void AddGamepadToPlatformService(uint32_t aPromiseId,
+                                   const GamepadAdded& aGamepadAdded);
+
+  nsTArray<DeferredGamepadAdded> mDeferredGamepadAdded;
+};
+
+}  // namespace mozilla::dom
+
+#endif
diff --git a/dom/gamepad/ipc/PGamepadEventChannel.ipdl b/dom/gamepad/ipc/PGamepadEventChannel.ipdl
new file mode 100644
index 0000000000..dba6725bd4
--- /dev/null
+++ b/dom/gamepad/ipc/PGamepadEventChannel.ipdl
@@ -0,0 +1,31 @@
+/* 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 protocol PBackground;
+include "mozilla/dom/GamepadMessageUtils.h";
+include GamepadEventTypes;
+
+using mozilla::dom::GamepadHandle from "mozilla/dom/GamepadHandle.h";
+
+namespace mozilla {
+namespace dom {
+
+protocol PGamepadEventChannel {
+  manager PBackground;
+  parent:
+    async __delete__();
+
+    [Tainted] async VibrateHaptic(GamepadHandle aHandle, uint32_t aHapticIndex,
+                                  double aIntensity, double aDuration, [NoTaint=passback] uint32_t aPromiseID);
+    [Tainted] async StopVibrateHaptic(GamepadHandle aHandle);
+    [Tainted] async LightIndicatorColor(GamepadHandle aHandle, uint32_t aLightColorIndex,
+                                        [NoTaint=allvalid] uint8_t aRed, [NoTaint=allvalid] uint8_t aGreen,
+                                        [NoTaint=allvalid] uint8_t aBlue, [NoTaint=passback] uint32_t aPromiseID);
+
+  child:
+    async GamepadUpdate(GamepadChangeEvent aGamepadEvent);
+    async ReplyGamepadPromise(uint32_t aPromiseID);
+};
+
+}
+}
diff --git a/dom/gamepad/ipc/PGamepadTestChannel.ipdl b/dom/gamepad/ipc/PGamepadTestChannel.ipdl
new file mode 100644
index 0000000000..2be0819491
--- /dev/null
+++ b/dom/gamepad/ipc/PGamepadTestChannel.ipdl
@@ -0,0 +1,23 @@
+/* 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 protocol PBackground;
+include "mozilla/dom/GamepadMessageUtils.h";
+include GamepadEventTypes;
+
+using mozilla::dom::GamepadHandle from "mozilla/dom/GamepadHandle.h";
+
+namespace mozilla {
+namespace dom {
+
+protocol PGamepadTestChannel {
+  manager PBackground;
+  parent:
+    async GamepadTestEvent(uint32_t aID, GamepadChangeEvent aGamepadEvent);
+    async __delete__();
+  child:
+    async ReplyGamepadHandle(uint32_t aID, GamepadHandle aHandle);
+};
+
+}
+}
diff --git a/dom/gamepad/linux/LinuxGamepad.cpp b/dom/gamepad/linux/LinuxGamepad.cpp
new file mode 100644
index 0000000000..e7a7071b86
--- /dev/null
+++ b/dom/gamepad/linux/LinuxGamepad.cpp
@@ -0,0 +1,529 @@
+/* -*- 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/. */
+
+/*
+ * LinuxGamepadService: An evdev backend for the GamepadService.
+ *
+ * Ref: https://www.kernel.org/doc/html/latest/input/gamepad.html
+ */
+#include <algorithm>
+#include <unordered_map>
+#include <cstddef>
+
+#include <glib.h>
+#include <linux/input.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+#include "nscore.h"
+#include "mozilla/dom/GamepadHandle.h"
+#include "mozilla/dom/GamepadPlatformService.h"
+#include "mozilla/dom/GamepadRemapping.h"
+#include "mozilla/Tainting.h"
+#include "mozilla/UniquePtr.h"
+#include "mozilla/Sprintf.h"
+#include "udev.h"
+
+#define BITS_PER_LONG ((sizeof(unsigned long)) * 8)
+#define BITS_TO_LONGS(x) (((x) + BITS_PER_LONG - 1) / BITS_PER_LONG)
+
+namespace {
+
+using namespace mozilla::dom;
+using mozilla::MakeUnique;
+using mozilla::udev_device;
+using mozilla::udev_enumerate;
+using mozilla::udev_lib;
+using mozilla::udev_list_entry;
+using mozilla::udev_monitor;
+using mozilla::UniquePtr;
+
+static const char kEvdevPath[] = "/dev/input/event";
+
+static inline bool TestBit(const unsigned long* arr, size_t bit) {
+  return !!(arr[bit / BITS_PER_LONG] & (1LL << (bit % BITS_PER_LONG)));
+}
+
+static inline double ScaleAxis(const input_absinfo& info, int value) {
+  return 2.0 * (value - info.minimum) / (double)(info.maximum - info.minimum) -
+         1.0;
+}
+
+// TODO: should find a USB identifier for each device so we can
+// provide something that persists across connect/disconnect cycles.
+struct Gamepad {
+  GamepadHandle handle;
+  bool isStandardGamepad = false;
+  RefPtr<GamepadRemapper> remapper = nullptr;
+  guint source_id = UINT_MAX;
+  char idstring[256] = {0};
+  char devpath[PATH_MAX] = {0};
+  uint8_t key_map[KEY_MAX] = {0};
+  uint8_t abs_map[ABS_MAX] = {0};
+  std::unordered_map<uint16_t, input_absinfo> abs_info;
+};
+
+static inline bool LoadAbsInfo(int fd, Gamepad* gamepad, uint16_t code) {
+  input_absinfo info{0};
+  if (ioctl(fd, EVIOCGABS(code), &info) < 0) {
+    return false;
+  }
+  if (info.minimum == info.maximum) {
+    return false;
+  }
+  gamepad->abs_info.emplace(code, std::move(info));
+  return true;
+}
+
+class LinuxGamepadService {
+ public:
+  LinuxGamepadService() : mMonitor(nullptr), mMonitorSourceID(0) {}
+
+  void Startup();
+  void Shutdown();
+
+ private:
+  void AddDevice(struct udev_device* dev);
+  void RemoveDevice(struct udev_device* dev);
+  void ScanForDevices();
+  void AddMonitor();
+  void RemoveMonitor();
+  bool IsDeviceGamepad(struct udev_device* dev);
+  void ReadUdevChange();
+
+  // handler for data from /dev/input/eventN
+  static gboolean OnGamepadData(GIOChannel* source, GIOCondition condition,
+                                gpointer data);
+
+  // handler for data from udev monitor
+  static gboolean OnUdevMonitor(GIOChannel* source, GIOCondition condition,
+                                gpointer data);
+
+  udev_lib mUdev;
+  struct udev_monitor* mMonitor;
+  guint mMonitorSourceID;
+  // Information about currently connected gamepads.
+  AutoTArray<UniquePtr<Gamepad>, 4> mGamepads;
+};
+
+// singleton instance
+LinuxGamepadService* gService = nullptr;
+
+void LinuxGamepadService::AddDevice(struct udev_device* dev) {
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  if (!service) {
+    return;
+  }
+
+  const char* devpath = mUdev.udev_device_get_devnode(dev);
+  if (!devpath) {
+    return;
+  }
+
+  // Ensure that this device hasn't already been added.
+  for (unsigned int i = 0; i < mGamepads.Length(); i++) {
+    if (strcmp(mGamepads[i]->devpath, devpath) == 0) {
+      return;
+    }
+  }
+
+  auto gamepad = MakeUnique<Gamepad>();
+  snprintf(gamepad->devpath, sizeof(gamepad->devpath), "%s", devpath);
+  GIOChannel* channel = g_io_channel_new_file(devpath, "r", nullptr);
+  if (!channel) {
+    return;
+  }
+
+  g_io_channel_set_flags(channel, G_IO_FLAG_NONBLOCK, nullptr);
+  g_io_channel_set_encoding(channel, nullptr, nullptr);
+  g_io_channel_set_buffered(channel, FALSE);
+  int fd = g_io_channel_unix_get_fd(channel);
+
+  input_id id{0};
+  if (ioctl(fd, EVIOCGID, &id) < 0) {
+    return;
+  }
+
+  char name[128]{0};
+  if (ioctl(fd, EVIOCGNAME(sizeof(name)), &name) < 0) {
+    strcpy(name, "Unknown Device");
+  }
+
+  SprintfLiteral(gamepad->idstring, "%04" PRIx16 "-%04" PRIx16 "-%s", id.vendor,
+                 id.product, name);
+
+  unsigned long keyBits[BITS_TO_LONGS(KEY_CNT)] = {0};
+  unsigned long absBits[BITS_TO_LONGS(ABS_CNT)] = {0};
+  if (ioctl(fd, EVIOCGBIT(EV_KEY, sizeof(keyBits)), keyBits) < 0 ||
+      ioctl(fd, EVIOCGBIT(EV_ABS, sizeof(absBits)), absBits) < 0) {
+    return;
+  }
+
+  /* Here, we try to support even strange cases where proper semantic
+   * BTN_GAMEPAD button are combined with arbitrary extra buttons. */
+
+  /* These are mappings where the index is a CanonicalButtonIndex and the value
+   * is an evdev code */
+  const std::array<uint16_t, BUTTON_INDEX_COUNT> kStandardButtons = {
+      /* BUTTON_INDEX_PRIMARY = */ BTN_SOUTH,
+      /* BUTTON_INDEX_SECONDARY = */ BTN_EAST,
+      /* BUTTON_INDEX_TERTIARY = */ BTN_WEST,
+      /* BUTTON_INDEX_QUATERNARY = */ BTN_NORTH,
+      /* BUTTON_INDEX_LEFT_SHOULDER = */ BTN_TL,
+      /* BUTTON_INDEX_RIGHT_SHOULDER = */ BTN_TR,
+      /* BUTTON_INDEX_LEFT_TRIGGER = */ BTN_TL2,
+      /* BUTTON_INDEX_RIGHT_TRIGGER = */ BTN_TR2,
+      /* BUTTON_INDEX_BACK_SELECT = */ BTN_SELECT,
+      /* BUTTON_INDEX_START = */ BTN_START,
+      /* BUTTON_INDEX_LEFT_THUMBSTICK = */ BTN_THUMBL,
+      /* BUTTON_INDEX_RIGHT_THUMBSTICK = */ BTN_THUMBR,
+      /* BUTTON_INDEX_DPAD_UP = */ BTN_DPAD_UP,
+      /* BUTTON_INDEX_DPAD_DOWN = */ BTN_DPAD_DOWN,
+      /* BUTTON_INDEX_DPAD_LEFT = */ BTN_DPAD_LEFT,
+      /* BUTTON_INDEX_DPAD_RIGHT = */ BTN_DPAD_RIGHT,
+      /* BUTTON_INDEX_META = */ BTN_MODE,
+  };
+  const std::array<uint16_t, AXIS_INDEX_COUNT> kStandardAxes = {
+      /* AXIS_INDEX_LEFT_STICK_X = */ ABS_X,
+      /* AXIS_INDEX_LEFT_STICK_Y = */ ABS_Y,
+      /* AXIS_INDEX_RIGHT_STICK_X = */ ABS_RX,
+      /* AXIS_INDEX_RIGHT_STICK_Y = */ ABS_RY,
+  };
+
+  /*
+   * According to https://www.kernel.org/doc/html/latest/input/gamepad.html,
+   * "All gamepads that follow the protocol described here map BTN_GAMEPAD",
+   * so we can use it as a proxy for semantic buttons in general. If it's
+   * enabled, we're probably going to be acting like a standard gamepad
+   */
+  uint32_t numButtons = 0;
+  if (TestBit(keyBits, BTN_GAMEPAD)) {
+    gamepad->isStandardGamepad = true;
+    for (uint8_t button = 0; button < BUTTON_INDEX_COUNT; button++) {
+      gamepad->key_map[kStandardButtons[button]] = button;
+    }
+    numButtons = BUTTON_INDEX_COUNT;
+  }
+
+  // Now, go through the non-semantic buttons and handle them as extras
+  for (uint16_t key = 0; key < KEY_MAX; key++) {
+    // Skip standard buttons
+    if (gamepad->isStandardGamepad &&
+        std::find(kStandardButtons.begin(), kStandardButtons.end(), key) !=
+            kStandardButtons.end()) {
+      continue;
+    }
+
+    if (TestBit(keyBits, key)) {
+      gamepad->key_map[key] = numButtons++;
+    }
+  }
+
+  uint32_t numAxes = 0;
+  if (gamepad->isStandardGamepad) {
+    for (uint8_t i = 0; i < AXIS_INDEX_COUNT; i++) {
+      gamepad->abs_map[kStandardAxes[i]] = i;
+      LoadAbsInfo(fd, gamepad.get(), kStandardAxes[i]);
+    }
+    numAxes = AXIS_INDEX_COUNT;
+
+    // These are not real axis and get remapped to buttons.
+    LoadAbsInfo(fd, gamepad.get(), ABS_HAT0X);
+    LoadAbsInfo(fd, gamepad.get(), ABS_HAT0Y);
+  }
+
+  for (uint16_t i = 0; i < ABS_MAX; ++i) {
+    if (gamepad->isStandardGamepad &&
+        (std::find(kStandardAxes.begin(), kStandardAxes.end(), i) !=
+             kStandardAxes.end() ||
+         i == ABS_HAT0X || i == ABS_HAT0Y)) {
+      continue;
+    }
+
+    if (TestBit(absBits, i)) {
+      if (LoadAbsInfo(fd, gamepad.get(), i)) {
+        gamepad->abs_map[i] = numAxes++;
+      }
+    }
+  }
+
+  if (numAxes == 0) {
+    NS_WARNING("Gamepad with zero axes detected?");
+  }
+  if (numButtons == 0) {
+    NS_WARNING("Gamepad with zero buttons detected?");
+  }
+
+  // NOTE: This almost always true, so we basically never use the remapping
+  // code.
+  if (gamepad->isStandardGamepad) {
+    gamepad->handle =
+        service->AddGamepad(gamepad->idstring, GamepadMappingType::Standard,
+                            GamepadHand::_empty, numButtons, numAxes, 0, 0, 0);
+  } else {
+    bool defaultRemapper = false;
+    RefPtr<GamepadRemapper> remapper =
+        GetGamepadRemapper(id.vendor, id.product, defaultRemapper);
+    MOZ_ASSERT(remapper);
+    remapper->SetAxisCount(numAxes);
+    remapper->SetButtonCount(numButtons);
+
+    gamepad->handle = service->AddGamepad(
+        gamepad->idstring, remapper->GetMappingType(), GamepadHand::_empty,
+        remapper->GetButtonCount(), remapper->GetAxisCount(), 0,
+        remapper->GetLightIndicatorCount(), remapper->GetTouchEventCount());
+    gamepad->remapper = remapper.forget();
+  }
+  // TODO: Bug 680289, implement gamepad haptics for Linux.
+  // TODO: Bug 1523355, implement gamepad lighindicator and touch for Linux.
+
+  gamepad->source_id =
+      g_io_add_watch(channel, GIOCondition(G_IO_IN | G_IO_ERR | G_IO_HUP),
+                     OnGamepadData, gamepad.get());
+  g_io_channel_unref(channel);
+
+  mGamepads.AppendElement(std::move(gamepad));
+}
+
+void LinuxGamepadService::RemoveDevice(struct udev_device* dev) {
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  if (!service) {
+    return;
+  }
+
+  const char* devpath = mUdev.udev_device_get_devnode(dev);
+  if (!devpath) {
+    return;
+  }
+
+  for (unsigned int i = 0; i < mGamepads.Length(); i++) {
+    if (strcmp(mGamepads[i]->devpath, devpath) == 0) {
+      auto gamepad = std::move(mGamepads[i]);
+      mGamepads.RemoveElementAt(i);
+
+      g_source_remove(gamepad->source_id);
+      service->RemoveGamepad(gamepad->handle);
+
+      break;
+    }
+  }
+}
+
+void LinuxGamepadService::ScanForDevices() {
+  struct udev_enumerate* en = mUdev.udev_enumerate_new(mUdev.udev);
+  mUdev.udev_enumerate_add_match_subsystem(en, "input");
+  mUdev.udev_enumerate_scan_devices(en);
+
+  struct udev_list_entry* dev_list_entry;
+  for (dev_list_entry = mUdev.udev_enumerate_get_list_entry(en);
+       dev_list_entry != nullptr;
+       dev_list_entry = mUdev.udev_list_entry_get_next(dev_list_entry)) {
+    const char* path = mUdev.udev_list_entry_get_name(dev_list_entry);
+    struct udev_device* dev =
+        mUdev.udev_device_new_from_syspath(mUdev.udev, path);
+    if (IsDeviceGamepad(dev)) {
+      AddDevice(dev);
+    }
+
+    mUdev.udev_device_unref(dev);
+  }
+
+  mUdev.udev_enumerate_unref(en);
+}
+
+void LinuxGamepadService::AddMonitor() {
+  // Add a monitor to watch for device changes
+  mMonitor = mUdev.udev_monitor_new_from_netlink(mUdev.udev, "udev");
+  if (!mMonitor) {
+    // Not much we can do here.
+    return;
+  }
+  mUdev.udev_monitor_filter_add_match_subsystem_devtype(mMonitor, "input",
+                                                        nullptr);
+
+  int monitor_fd = mUdev.udev_monitor_get_fd(mMonitor);
+  GIOChannel* monitor_channel = g_io_channel_unix_new(monitor_fd);
+  mMonitorSourceID = g_io_add_watch(monitor_channel,
+                                    GIOCondition(G_IO_IN | G_IO_ERR | G_IO_HUP),
+                                    OnUdevMonitor, nullptr);
+  g_io_channel_unref(monitor_channel);
+
+  mUdev.udev_monitor_enable_receiving(mMonitor);
+}
+
+void LinuxGamepadService::RemoveMonitor() {
+  if (mMonitorSourceID) {
+    g_source_remove(mMonitorSourceID);
+    mMonitorSourceID = 0;
+  }
+  if (mMonitor) {
+    mUdev.udev_monitor_unref(mMonitor);
+    mMonitor = nullptr;
+  }
+}
+
+void LinuxGamepadService::Startup() {
+  // Don't bother starting up if libudev couldn't be loaded or initialized.
+  if (!mUdev) {
+    return;
+  }
+
+  AddMonitor();
+  ScanForDevices();
+}
+
+void LinuxGamepadService::Shutdown() {
+  for (unsigned int i = 0; i < mGamepads.Length(); i++) {
+    g_source_remove(mGamepads[i]->source_id);
+  }
+  mGamepads.Clear();
+  RemoveMonitor();
+}
+
+bool LinuxGamepadService::IsDeviceGamepad(struct udev_device* aDev) {
+  if (!mUdev.udev_device_get_property_value(aDev, "ID_INPUT_JOYSTICK")) {
+    return false;
+  }
+
+  const char* devpath = mUdev.udev_device_get_devnode(aDev);
+  if (!devpath) {
+    return false;
+  }
+
+  return strncmp(devpath, kEvdevPath, strlen(kEvdevPath)) == 0;
+}
+
+void LinuxGamepadService::ReadUdevChange() {
+  struct udev_device* dev = mUdev.udev_monitor_receive_device(mMonitor);
+  if (IsDeviceGamepad(dev)) {
+    const char* action = mUdev.udev_device_get_action(dev);
+    if (strcmp(action, "add") == 0) {
+      AddDevice(dev);
+    } else if (strcmp(action, "remove") == 0) {
+      RemoveDevice(dev);
+    }
+  }
+  mUdev.udev_device_unref(dev);
+}
+
+// static
+gboolean LinuxGamepadService::OnGamepadData(GIOChannel* source,
+                                            GIOCondition condition,
+                                            gpointer data) {
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  if (!service) {
+    return TRUE;
+  }
+  auto* gamepad = static_cast<Gamepad*>(data);
+
+  // TODO: remove gamepad?
+  if (condition & (G_IO_ERR | G_IO_HUP)) {
+    return FALSE;
+  }
+
+  while (true) {
+    struct input_event event {};
+    gsize count;
+    GError* err = nullptr;
+    if (g_io_channel_read_chars(source, (gchar*)&event, sizeof(event), &count,
+                                &err) != G_IO_STATUS_NORMAL ||
+        count == 0) {
+      break;
+    }
+
+    switch (event.type) {
+      case EV_KEY:
+        if (gamepad->isStandardGamepad) {
+          service->NewButtonEvent(gamepad->handle, gamepad->key_map[event.code],
+                                  !!event.value);
+        } else {
+          gamepad->remapper->RemapButtonEvent(
+              gamepad->handle, gamepad->key_map[event.code], !!event.value);
+        }
+        break;
+      case EV_ABS: {
+        if (!gamepad->abs_info.count(event.code)) {
+          continue;
+        }
+
+        double scaledValue =
+            ScaleAxis(gamepad->abs_info[event.code], event.value);
+        if (gamepad->isStandardGamepad) {
+          switch (event.code) {
+            case ABS_HAT0X:
+              service->NewButtonEvent(gamepad->handle, BUTTON_INDEX_DPAD_LEFT,
+                                      AxisNegativeAsButton(scaledValue));
+              service->NewButtonEvent(gamepad->handle, BUTTON_INDEX_DPAD_RIGHT,
+                                      AxisPositiveAsButton(scaledValue));
+              break;
+            case ABS_HAT0Y:
+              service->NewButtonEvent(gamepad->handle, BUTTON_INDEX_DPAD_UP,
+                                      AxisNegativeAsButton(scaledValue));
+              service->NewButtonEvent(gamepad->handle, BUTTON_INDEX_DPAD_DOWN,
+                                      AxisPositiveAsButton(scaledValue));
+              break;
+            default:
+              service->NewAxisMoveEvent(
+                  gamepad->handle, gamepad->abs_map[event.code], scaledValue);
+              break;
+          }
+        } else {
+          gamepad->remapper->RemapAxisMoveEvent(
+              gamepad->handle, gamepad->abs_map[event.code], scaledValue);
+        }
+      } break;
+    }
+  }
+
+  return TRUE;
+}
+
+// static
+gboolean LinuxGamepadService::OnUdevMonitor(GIOChannel* source,
+                                            GIOCondition condition,
+                                            gpointer data) {
+  if (condition & (G_IO_ERR | G_IO_HUP)) {
+    return FALSE;
+  }
+
+  gService->ReadUdevChange();
+  return TRUE;
+}
+
+}  // namespace
+
+namespace mozilla::dom {
+
+void StartGamepadMonitoring() {
+  if (gService) {
+    return;
+  }
+  gService = new LinuxGamepadService();
+  gService->Startup();
+}
+
+void StopGamepadMonitoring() {
+  if (!gService) {
+    return;
+  }
+  gService->Shutdown();
+  delete gService;
+  gService = nullptr;
+}
+
+void SetGamepadLightIndicatorColor(const Tainted<GamepadHandle>& aGamepadHandle,
+                                   const Tainted<uint32_t>& aLightColorIndex,
+                                   const uint8_t& aRed, const uint8_t& aGreen,
+                                   const uint8_t& aBlue) {
+  // TODO: Bug 1523355.
+  NS_WARNING("Linux doesn't support gamepad light indicator.");
+}
+
+}  // namespace mozilla::dom
diff --git a/dom/gamepad/linux/udev.h b/dom/gamepad/linux/udev.h
new file mode 100644
index 0000000000..4e3f0b7865
--- /dev/null
+++ b/dom/gamepad/linux/udev.h
@@ -0,0 +1,150 @@
+/* -*- 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/. */
+
+/*
+ * This file defines a wrapper around libudev so we can avoid
+ * linking directly to it and use dlopen instead.
+ */
+
+#ifndef HAL_LINUX_UDEV_H_
+#define HAL_LINUX_UDEV_H_
+
+#include <dlfcn.h>
+
+#include "mozilla/ArrayUtils.h"
+
+namespace mozilla {
+
+struct udev;
+struct udev_device;
+struct udev_enumerate;
+struct udev_list_entry;
+struct udev_monitor;
+
+class udev_lib {
+ public:
+  udev_lib() : lib(nullptr), udev(nullptr) {
+    // Be careful about ABI compat! 0 -> 1 didn't change any
+    // symbols this code relies on, per:
+    // https://lists.fedoraproject.org/pipermail/devel/2012-June/168227.html
+    const char* lib_names[] = {"libudev.so.0", "libudev.so.1"};
+    // Check whether a library is already loaded so we don't load two
+    // conflicting libs.
+    for (unsigned i = 0; i < ArrayLength(lib_names); i++) {
+      lib = dlopen(lib_names[i], RTLD_NOLOAD | RTLD_LAZY | RTLD_GLOBAL);
+      if (lib) {
+        break;
+      }
+    }
+    // If nothing loads the first time through, it means no version of libudev
+    // was already loaded.
+    if (!lib) {
+      for (unsigned i = 0; i < ArrayLength(lib_names); i++) {
+        lib = dlopen(lib_names[i], RTLD_LAZY | RTLD_GLOBAL);
+        if (lib) {
+          break;
+        }
+      }
+    }
+    if (lib && LoadSymbols()) {
+      udev = udev_new();
+    }
+  }
+
+  ~udev_lib() {
+    if (udev) {
+      udev_unref(udev);
+    }
+
+    if (lib) {
+      dlclose(lib);
+    }
+  }
+
+  explicit operator bool() { return udev; }
+
+ private:
+#define DLSYM(s)                       \
+  do {                                 \
+    (s) = (decltype(s))dlsym(lib, #s); \
+    if (!(s)) return false;            \
+  } while (0)
+
+  bool LoadSymbols() {
+    DLSYM(udev_new);
+    DLSYM(udev_unref);
+    DLSYM(udev_device_unref);
+    DLSYM(udev_device_new_from_syspath);
+    DLSYM(udev_device_get_devnode);
+    DLSYM(udev_device_get_parent_with_subsystem_devtype);
+    DLSYM(udev_device_get_property_value);
+    DLSYM(udev_device_get_action);
+    DLSYM(udev_device_get_sysattr_value);
+    DLSYM(udev_enumerate_new);
+    DLSYM(udev_enumerate_unref);
+    DLSYM(udev_enumerate_add_match_subsystem);
+    DLSYM(udev_enumerate_scan_devices);
+    DLSYM(udev_enumerate_get_list_entry);
+    DLSYM(udev_list_entry_get_next);
+    DLSYM(udev_list_entry_get_name);
+    DLSYM(udev_monitor_new_from_netlink);
+    DLSYM(udev_monitor_filter_add_match_subsystem_devtype);
+    DLSYM(udev_monitor_enable_receiving);
+    DLSYM(udev_monitor_get_fd);
+    DLSYM(udev_monitor_receive_device);
+    DLSYM(udev_monitor_unref);
+
+    return true;
+  }
+
+#undef DLSYM
+
+  void* lib;
+
+ public:
+  struct udev* udev;
+
+  // Function pointers returned from dlsym.
+  struct udev* (*udev_new)(void);
+  void (*udev_unref)(struct udev*);
+
+  void (*udev_device_unref)(struct udev_device*);
+  struct udev_device* (*udev_device_new_from_syspath)(struct udev*,
+                                                      const char*);
+  const char* (*udev_device_get_devnode)(struct udev_device*);
+  struct udev_device* (*udev_device_get_parent_with_subsystem_devtype)(
+      struct udev_device*, const char*, const char*);
+  const char* (*udev_device_get_property_value)(struct udev_device*,
+                                                const char*);
+  const char* (*udev_device_get_action)(struct udev_device*);
+  const char* (*udev_device_get_sysattr_value)(struct udev_device*,
+                                               const char*);
+
+  struct udev_enumerate* (*udev_enumerate_new)(struct udev*);
+  void (*udev_enumerate_unref)(struct udev_enumerate*);
+  int (*udev_enumerate_add_match_subsystem)(struct udev_enumerate*,
+                                            const char*);
+  int (*udev_enumerate_scan_devices)(struct udev_enumerate*);
+  struct udev_list_entry* (*udev_enumerate_get_list_entry)(
+      struct udev_enumerate*);
+
+  struct udev_list_entry* (*udev_list_entry_get_next)(struct udev_list_entry*);
+  const char* (*udev_list_entry_get_name)(struct udev_list_entry*);
+
+  struct udev_monitor* (*udev_monitor_new_from_netlink)(struct udev*,
+                                                        const char*);
+  int (*udev_monitor_filter_add_match_subsystem_devtype)(struct udev_monitor*,
+                                                         const char*,
+                                                         const char*);
+  int (*udev_monitor_enable_receiving)(struct udev_monitor*);
+  int (*udev_monitor_get_fd)(struct udev_monitor*);
+  struct udev_device* (*udev_monitor_receive_device)(struct udev_monitor*);
+  void (*udev_monitor_unref)(struct udev_monitor*);
+};
+
+}  // namespace mozilla
+
+#endif  // HAL_LINUX_UDEV_H_
diff --git a/dom/gamepad/moz.build b/dom/gamepad/moz.build
new file mode 100644
index 0000000000..db77ef8da6
--- /dev/null
+++ b/dom/gamepad/moz.build
@@ -0,0 +1,79 @@
+# -*- 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/.
+
+with Files("**"):
+    BUG_COMPONENT = ("Core", "DOM: Device Interfaces")
+
+IPDL_SOURCES += [
+    "ipc/GamepadEventTypes.ipdlh",
+    "ipc/PGamepadEventChannel.ipdl",
+    "ipc/PGamepadTestChannel.ipdl",
+]
+
+EXPORTS.mozilla.dom += [
+    "Gamepad.h",
+    "GamepadButton.h",
+    "GamepadHandle.h",
+    "GamepadHapticActuator.h",
+    "GamepadLightIndicator.h",
+    "GamepadManager.h",
+    "GamepadMonitoring.h",
+    "GamepadPlatformService.h",
+    "GamepadPose.h",
+    "GamepadPoseState.h",
+    "GamepadRemapping.h",
+    "GamepadServiceTest.h",
+    "GamepadTouch.h",
+    "GamepadTouchState.h",
+    "ipc/GamepadEventChannelChild.h",
+    "ipc/GamepadEventChannelParent.h",
+    "ipc/GamepadMessageUtils.h",
+    "ipc/GamepadTestChannelChild.h",
+    "ipc/GamepadTestChannelParent.h",
+]
+
+UNIFIED_SOURCES = [
+    "Gamepad.cpp",
+    "GamepadButton.cpp",
+    "GamepadHandle.cpp",
+    "GamepadHapticActuator.cpp",
+    "GamepadLightIndicator.cpp",
+    "GamepadManager.cpp",
+    "GamepadPlatformService.cpp",
+    "GamepadPose.cpp",
+    "GamepadRemapping.cpp",
+    "GamepadServiceTest.cpp",
+    "GamepadTouch.cpp",
+    "ipc/GamepadEventChannelChild.cpp",
+    "ipc/GamepadEventChannelParent.cpp",
+    "ipc/GamepadTestChannelChild.cpp",
+    "ipc/GamepadTestChannelParent.cpp",
+]
+
+if CONFIG["MOZ_WIDGET_TOOLKIT"] == "cocoa":
+    UNIFIED_SOURCES += ["cocoa/CocoaGamepad.cpp"]
+elif CONFIG["MOZ_WIDGET_TOOLKIT"] == "windows":
+    UNIFIED_SOURCES += ["windows/WindowsGamepad.cpp"]
+elif CONFIG["MOZ_WIDGET_TOOLKIT"] == "android":
+    UNIFIED_SOURCES += ["android/AndroidGamepad.cpp"]
+elif CONFIG["OS_ARCH"] in ("Linux", "FreeBSD", "DragonFly"):
+    UNIFIED_SOURCES += ["linux/LinuxGamepad.cpp"]
+else:
+    UNIFIED_SOURCES += ["fallback/FallbackGamepad.cpp"]
+
+LOCAL_INCLUDES += [
+    "ipc",
+]
+
+include("/ipc/chromium/chromium-config.mozbuild")
+
+FINAL_LIBRARY = "xul"
+LOCAL_INCLUDES += [
+    "/dom/base",
+]
+
+CFLAGS += CONFIG["GLIB_CFLAGS"]
+CXXFLAGS += CONFIG["GLIB_CFLAGS"]
diff --git a/dom/gamepad/windows/WindowsGamepad.cpp b/dom/gamepad/windows/WindowsGamepad.cpp
new file mode 100644
index 0000000000..d5584eaea8
--- /dev/null
+++ b/dom/gamepad/windows/WindowsGamepad.cpp
@@ -0,0 +1,1136 @@
+/* -*- 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 <algorithm>
+#include <cstddef>
+
+#ifndef UNICODE
+#  define UNICODE
+#endif
+#include <windows.h>
+#include <hidsdi.h>
+#include <stdio.h>
+#include <xinput.h>
+
+#include "nsITimer.h"
+#include "nsTArray.h"
+#include "nsThreadUtils.h"
+#include "nsWindowsHelpers.h"
+
+#include "mozilla/ArrayUtils.h"
+
+#include "mozilla/ipc/BackgroundParent.h"
+#include "mozilla/dom/GamepadPlatformService.h"
+#include "mozilla/dom/GamepadRemapping.h"
+#include "Gamepad.h"
+
+namespace {
+
+using namespace mozilla;
+using namespace mozilla::dom;
+using mozilla::ArrayLength;
+
+// USB HID usage tables, page 1, 0x30 = X
+const uint32_t kAxisMinimumUsageNumber = 0x30;
+// USB HID usage tables, page 1 (Hat switch)
+const uint32_t kAxesLengthCap = 16;
+
+// USB HID usage tables
+const uint32_t kDesktopUsagePage = 0x1;
+const uint32_t kButtonUsagePage = 0x9;
+
+// Multiple devices-changed notifications can be sent when a device
+// is connected, because USB devices consist of multiple logical devices.
+// Therefore, we wait a bit after receiving one before looking for
+// device changes.
+const uint32_t kDevicesChangedStableDelay = 200;
+// Both DirectInput and XInput are polling-driven here,
+// so we need to poll it periodically.
+// 4ms, or 250 Hz, is consistent with Chrome's gamepad implementation.
+const uint32_t kWindowsGamepadPollInterval = 4;
+
+const UINT kRawInputError = (UINT)-1;
+
+// In XInputGetState, we can't get the state of Xbox Guide button.
+// We need to go through the undocumented XInputGetStateEx method
+// to get that button's state.
+const LPCSTR kXInputGetStateExOrdinal = (LPCSTR)100;
+// Bitmask for the Guide button in XInputGamepadEx.wButtons.
+const int XINPUT_GAMEPAD_Guide = 0x0400;
+
+#ifndef XUSER_MAX_COUNT
+#  define XUSER_MAX_COUNT 4
+#endif
+
+const struct {
+  int usagePage;
+  int usage;
+} kUsagePages[] = {
+    // USB HID usage tables, page 1
+    {kDesktopUsagePage, 4},  // Joystick
+    {kDesktopUsagePage, 5}   // Gamepad
+};
+
+const struct {
+  WORD button;
+  int mapped;
+} kXIButtonMap[] = {{XINPUT_GAMEPAD_DPAD_UP, 12},
+                    {XINPUT_GAMEPAD_DPAD_DOWN, 13},
+                    {XINPUT_GAMEPAD_DPAD_LEFT, 14},
+                    {XINPUT_GAMEPAD_DPAD_RIGHT, 15},
+                    {XINPUT_GAMEPAD_START, 9},
+                    {XINPUT_GAMEPAD_BACK, 8},
+                    {XINPUT_GAMEPAD_LEFT_THUMB, 10},
+                    {XINPUT_GAMEPAD_RIGHT_THUMB, 11},
+                    {XINPUT_GAMEPAD_LEFT_SHOULDER, 4},
+                    {XINPUT_GAMEPAD_RIGHT_SHOULDER, 5},
+                    {XINPUT_GAMEPAD_Guide, 16},
+                    {XINPUT_GAMEPAD_A, 0},
+                    {XINPUT_GAMEPAD_B, 1},
+                    {XINPUT_GAMEPAD_X, 2},
+                    {XINPUT_GAMEPAD_Y, 3}};
+const size_t kNumMappings = ArrayLength(kXIButtonMap);
+
+enum GamepadType { kNoGamepad = 0, kRawInputGamepad, kXInputGamepad };
+
+class WindowsGamepadService;
+// This pointer holds a windows gamepad backend service,
+// it will be created and destroyed by background thread and
+// used by gMonitorThread
+WindowsGamepadService* MOZ_NON_OWNING_REF gService = nullptr;
+nsCOMPtr<nsIThread> gMonitorThread = nullptr;
+static bool sIsShutdown = false;
+
+class Gamepad {
+ public:
+  GamepadType type;
+
+  // Handle to raw input device
+  HANDLE handle;
+
+  // XInput Index of the user's controller. Passed to XInputGetState.
+  DWORD userIndex;
+
+  // Last-known state of the controller.
+  XINPUT_STATE state;
+
+  // Handle from the GamepadService
+  GamepadHandle gamepadHandle;
+
+  // Information about the physical device.
+  unsigned numAxes;
+  unsigned numButtons;
+
+  nsTArray<bool> buttons;
+  struct axisValue {
+    HIDP_VALUE_CAPS caps;
+    double value;
+    bool active;
+
+    axisValue() : value(0.0f), active(false) {}
+    explicit axisValue(const HIDP_VALUE_CAPS& aCaps)
+        : caps(aCaps), value(0.0f), active(true) {}
+  };
+  nsTArray<axisValue> axes;
+
+  RefPtr<GamepadRemapper> remapper;
+
+  // Used during rescan to find devices that were disconnected.
+  bool present;
+
+  Gamepad(uint32_t aNumAxes, uint32_t aNumButtons, GamepadType aType)
+      : type(aType), numAxes(aNumAxes), numButtons(aNumButtons), present(true) {
+    buttons.SetLength(numButtons);
+    axes.SetLength(numAxes);
+  }
+
+ private:
+  Gamepad() {}
+};
+
+// Drop this in favor of decltype when we require a new enough SDK.
+using XInputEnable_func = void(WINAPI*)(BOOL);
+
+// RAII class to wrap loading the XInput DLL
+class XInputLoader {
+ public:
+  XInputLoader()
+      : module(nullptr), mXInputGetState(nullptr), mXInputEnable(nullptr) {
+    // xinput1_4.dll exists on Windows 8
+    // xinput9_1_0.dll exists on Windows 7 and Vista
+    // xinput1_3.dll shipped with the DirectX SDK
+    const wchar_t* dlls[] = {L"xinput1_4.dll", L"xinput9_1_0.dll",
+                             L"xinput1_3.dll"};
+    const size_t kNumDLLs = ArrayLength(dlls);
+    for (size_t i = 0; i < kNumDLLs; ++i) {
+      module = LoadLibraryW(dlls[i]);
+      if (module) {
+        mXInputEnable = reinterpret_cast<XInputEnable_func>(
+            GetProcAddress(module, "XInputEnable"));
+        // Checking if `XInputGetStateEx` is available. If not,
+        // we will fallback to use `XInputGetState`.
+        mXInputGetState = reinterpret_cast<decltype(XInputGetState)*>(
+            GetProcAddress(module, kXInputGetStateExOrdinal));
+        if (!mXInputGetState) {
+          mXInputGetState = reinterpret_cast<decltype(XInputGetState)*>(
+              GetProcAddress(module, "XInputGetState"));
+        }
+        MOZ_ASSERT(mXInputGetState &&
+                   "XInputGetState must be linked successfully.");
+
+        if (mXInputEnable) {
+          mXInputEnable(TRUE);
+        }
+        break;
+      }
+    }
+  }
+
+  ~XInputLoader() {
+    mXInputEnable = nullptr;
+    mXInputGetState = nullptr;
+
+    if (module) {
+      FreeLibrary(module);
+    }
+  }
+
+  explicit operator bool() { return module && mXInputGetState; }
+
+  HMODULE module;
+  decltype(XInputGetState)* mXInputGetState;
+  XInputEnable_func mXInputEnable;
+};
+
+bool GetPreparsedData(HANDLE handle, nsTArray<uint8_t>& data) {
+  UINT size;
+  if (GetRawInputDeviceInfo(handle, RIDI_PREPARSEDDATA, nullptr, &size) ==
+      kRawInputError) {
+    return false;
+  }
+  data.SetLength(size);
+  return GetRawInputDeviceInfo(handle, RIDI_PREPARSEDDATA, data.Elements(),
+                               &size) > 0;
+}
+
+/*
+ * Given an axis value and a minimum and maximum range,
+ * scale it to be in the range -1.0 .. 1.0.
+ */
+double ScaleAxis(ULONG value, LONG min, LONG max) {
+  return 2.0 * (value - min) / (max - min) - 1.0;
+}
+
+/*
+ * Return true if this USB HID usage page and usage are of a type we
+ * know how to handle.
+ */
+bool SupportedUsage(USHORT page, USHORT usage) {
+  for (unsigned i = 0; i < ArrayLength(kUsagePages); i++) {
+    if (page == kUsagePages[i].usagePage && usage == kUsagePages[i].usage) {
+      return true;
+    }
+  }
+  return false;
+}
+
+class HIDLoader {
+ public:
+  HIDLoader()
+      : mHidD_GetProductString(nullptr),
+        mHidP_GetCaps(nullptr),
+        mHidP_GetButtonCaps(nullptr),
+        mHidP_GetValueCaps(nullptr),
+        mHidP_GetUsages(nullptr),
+        mHidP_GetUsageValue(nullptr),
+        mHidP_GetScaledUsageValue(nullptr),
+        mModule(LoadLibraryW(L"hid.dll")) {
+    if (mModule) {
+      mHidD_GetProductString =
+          reinterpret_cast<decltype(HidD_GetProductString)*>(
+              GetProcAddress(mModule, "HidD_GetProductString"));
+      mHidP_GetCaps = reinterpret_cast<decltype(HidP_GetCaps)*>(
+          GetProcAddress(mModule, "HidP_GetCaps"));
+      mHidP_GetButtonCaps = reinterpret_cast<decltype(HidP_GetButtonCaps)*>(
+          GetProcAddress(mModule, "HidP_GetButtonCaps"));
+      mHidP_GetValueCaps = reinterpret_cast<decltype(HidP_GetValueCaps)*>(
+          GetProcAddress(mModule, "HidP_GetValueCaps"));
+      mHidP_GetUsages = reinterpret_cast<decltype(HidP_GetUsages)*>(
+          GetProcAddress(mModule, "HidP_GetUsages"));
+      mHidP_GetUsageValue = reinterpret_cast<decltype(HidP_GetUsageValue)*>(
+          GetProcAddress(mModule, "HidP_GetUsageValue"));
+      mHidP_GetScaledUsageValue =
+          reinterpret_cast<decltype(HidP_GetScaledUsageValue)*>(
+              GetProcAddress(mModule, "HidP_GetScaledUsageValue"));
+    }
+  }
+
+  ~HIDLoader() {
+    if (mModule) {
+      FreeLibrary(mModule);
+    }
+  }
+
+  explicit operator bool() {
+    return mModule && mHidD_GetProductString && mHidP_GetCaps &&
+           mHidP_GetButtonCaps && mHidP_GetValueCaps && mHidP_GetUsages &&
+           mHidP_GetUsageValue && mHidP_GetScaledUsageValue;
+  }
+
+  decltype(HidD_GetProductString)* mHidD_GetProductString;
+  decltype(HidP_GetCaps)* mHidP_GetCaps;
+  decltype(HidP_GetButtonCaps)* mHidP_GetButtonCaps;
+  decltype(HidP_GetValueCaps)* mHidP_GetValueCaps;
+  decltype(HidP_GetUsages)* mHidP_GetUsages;
+  decltype(HidP_GetUsageValue)* mHidP_GetUsageValue;
+  decltype(HidP_GetScaledUsageValue)* mHidP_GetScaledUsageValue;
+
+ private:
+  HMODULE mModule;
+};
+
+HWND sHWnd = nullptr;
+
+static void DirectInputMessageLoopOnceCallback(nsITimer* aTimer,
+                                               void* aClosure) {
+  MOZ_ASSERT(NS_GetCurrentThread() == gMonitorThread);
+  MSG msg;
+  while (PeekMessageW(&msg, sHWnd, 0, 0, PM_REMOVE) > 0) {
+    TranslateMessage(&msg);
+    DispatchMessage(&msg);
+  }
+  aTimer->Cancel();
+  if (!sIsShutdown) {
+    aTimer->InitWithNamedFuncCallback(DirectInputMessageLoopOnceCallback,
+                                      nullptr, kWindowsGamepadPollInterval,
+                                      nsITimer::TYPE_ONE_SHOT,
+                                      "DirectInputMessageLoopOnceCallback");
+  }
+}
+
+class WindowsGamepadService {
+ public:
+  WindowsGamepadService() {
+    mDirectInputTimer = NS_NewTimer();
+    mXInputTimer = NS_NewTimer();
+    mDeviceChangeTimer = NS_NewTimer();
+  }
+  virtual ~WindowsGamepadService() { Cleanup(); }
+
+  void DevicesChanged(bool aIsStablizing);
+
+  void StartMessageLoop() {
+    MOZ_ASSERT(mDirectInputTimer);
+    mDirectInputTimer->InitWithNamedFuncCallback(
+        DirectInputMessageLoopOnceCallback, nullptr,
+        kWindowsGamepadPollInterval, nsITimer::TYPE_ONE_SHOT,
+        "DirectInputMessageLoopOnceCallback");
+  }
+
+  void Startup();
+  void Shutdown();
+  // Parse gamepad input from a WM_INPUT message.
+  bool HandleRawInput(HRAWINPUT handle);
+  void SetLightIndicatorColor(const Tainted<GamepadHandle>& aGamepadHandle,
+                              const Tainted<uint32_t>& aLightColorIndex,
+                              const uint8_t& aRed, const uint8_t& aGreen,
+                              const uint8_t& aBlue);
+  size_t WriteOutputReport(const std::vector<uint8_t>& aReport);
+  static void XInputMessageLoopOnceCallback(nsITimer* aTimer, void* aClosure);
+  static void DevicesChangeCallback(nsITimer* aTimer, void* aService);
+
+ private:
+  void ScanForDevices();
+  // Look for connected raw input devices.
+  void ScanForRawInputDevices();
+  // Look for connected XInput devices.
+  bool ScanForXInputDevices();
+  bool HaveXInputGamepad(unsigned int userIndex);
+
+  bool mIsXInputMonitoring;
+  void PollXInput();
+  void CheckXInputChanges(Gamepad& gamepad, XINPUT_STATE& state);
+
+  // Get information about a raw input gamepad.
+  bool GetRawGamepad(HANDLE handle);
+  void Cleanup();
+
+  // List of connected devices.
+  nsTArray<Gamepad> mGamepads;
+
+  HIDLoader mHID;
+  nsAutoHandle mHidHandle;
+  XInputLoader mXInput;
+
+  nsCOMPtr<nsITimer> mDirectInputTimer;
+  nsCOMPtr<nsITimer> mXInputTimer;
+  nsCOMPtr<nsITimer> mDeviceChangeTimer;
+};
+
+void WindowsGamepadService::ScanForRawInputDevices() {
+  if (!mHID) {
+    return;
+  }
+
+  UINT numDevices;
+  if (GetRawInputDeviceList(nullptr, &numDevices, sizeof(RAWINPUTDEVICELIST)) ==
+      kRawInputError) {
+    return;
+  }
+  nsTArray<RAWINPUTDEVICELIST> devices(numDevices);
+  devices.SetLength(numDevices);
+  if (GetRawInputDeviceList(devices.Elements(), &numDevices,
+                            sizeof(RAWINPUTDEVICELIST)) == kRawInputError) {
+    return;
+  }
+
+  for (unsigned i = 0; i < devices.Length(); i++) {
+    if (devices[i].dwType == RIM_TYPEHID) {
+      GetRawGamepad(devices[i].hDevice);
+    }
+  }
+}
+
+// static
+void WindowsGamepadService::XInputMessageLoopOnceCallback(nsITimer* aTimer,
+                                                          void* aService) {
+  MOZ_ASSERT(aService);
+  WindowsGamepadService* self = static_cast<WindowsGamepadService*>(aService);
+  self->PollXInput();
+  if (self->mIsXInputMonitoring) {
+    aTimer->Cancel();
+    aTimer->InitWithNamedFuncCallback(
+        XInputMessageLoopOnceCallback, self, kWindowsGamepadPollInterval,
+        nsITimer::TYPE_ONE_SHOT, "XInputMessageLoopOnceCallback");
+  }
+}
+
+// static
+void WindowsGamepadService::DevicesChangeCallback(nsITimer* aTimer,
+                                                  void* aService) {
+  MOZ_ASSERT(aService);
+  WindowsGamepadService* self = static_cast<WindowsGamepadService*>(aService);
+  self->DevicesChanged(false);
+}
+
+bool WindowsGamepadService::HaveXInputGamepad(unsigned int userIndex) {
+  for (unsigned int i = 0; i < mGamepads.Length(); i++) {
+    if (mGamepads[i].type == kXInputGamepad &&
+        mGamepads[i].userIndex == userIndex) {
+      mGamepads[i].present = true;
+      return true;
+    }
+  }
+  return false;
+}
+
+bool WindowsGamepadService::ScanForXInputDevices() {
+  MOZ_ASSERT(mXInput, "XInput should be present!");
+
+  bool found = false;
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  if (!service) {
+    return found;
+  }
+
+  for (unsigned int i = 0; i < XUSER_MAX_COUNT; i++) {
+    XINPUT_STATE state = {};
+
+    if (!mXInput.mXInputGetState ||
+        mXInput.mXInputGetState(i, &state) != ERROR_SUCCESS) {
+      continue;
+    }
+
+    found = true;
+    // See if this device is already present in our list.
+    if (HaveXInputGamepad(i)) {
+      continue;
+    }
+
+    // Not already present, add it.
+    Gamepad gamepad(kStandardGamepadAxes, kStandardGamepadButtons,
+                    kXInputGamepad);
+    gamepad.userIndex = i;
+    gamepad.state = state;
+    gamepad.gamepadHandle = service->AddGamepad(
+        "xinput", GamepadMappingType::Standard, GamepadHand::_empty,
+        kStandardGamepadButtons, kStandardGamepadAxes, 0, 0,
+        0);  // TODO: Bug 680289, implement gamepad haptics for Windows.
+    mGamepads.AppendElement(std::move(gamepad));
+  }
+
+  return found;
+}
+
+void WindowsGamepadService::ScanForDevices() {
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  if (!service) {
+    return;
+  }
+
+  for (int i = mGamepads.Length() - 1; i >= 0; i--) {
+    mGamepads[i].present = false;
+  }
+
+  if (mHID) {
+    ScanForRawInputDevices();
+  }
+  if (mXInput) {
+    mXInputTimer->Cancel();
+    if (ScanForXInputDevices()) {
+      mIsXInputMonitoring = true;
+      mXInputTimer->InitWithNamedFuncCallback(
+          XInputMessageLoopOnceCallback, this, kWindowsGamepadPollInterval,
+          nsITimer::TYPE_ONE_SHOT, "XInputMessageLoopOnceCallback");
+    } else {
+      mIsXInputMonitoring = false;
+    }
+  }
+
+  // Look for devices that are no longer present and remove them.
+  for (int i = mGamepads.Length() - 1; i >= 0; i--) {
+    if (!mGamepads[i].present) {
+      service->RemoveGamepad(mGamepads[i].gamepadHandle);
+      mGamepads.RemoveElementAt(i);
+    }
+  }
+}
+
+void WindowsGamepadService::PollXInput() {
+  for (unsigned int i = 0; i < mGamepads.Length(); i++) {
+    if (mGamepads[i].type != kXInputGamepad) {
+      continue;
+    }
+
+    XINPUT_STATE state = {};
+
+    if (!mXInput.mXInputGetState ||
+        mXInput.mXInputGetState(i, &state) != ERROR_SUCCESS) {
+      continue;
+    }
+
+    if (state.dwPacketNumber != mGamepads[i].state.dwPacketNumber) {
+      CheckXInputChanges(mGamepads[i], state);
+    }
+  }
+}
+
+void WindowsGamepadService::CheckXInputChanges(Gamepad& gamepad,
+                                               XINPUT_STATE& state) {
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  if (!service) {
+    return;
+  }
+  // Handle digital buttons first
+  for (size_t b = 0; b < kNumMappings; b++) {
+    if (state.Gamepad.wButtons & kXIButtonMap[b].button &&
+        !(gamepad.state.Gamepad.wButtons & kXIButtonMap[b].button)) {
+      // Button pressed
+      service->NewButtonEvent(gamepad.gamepadHandle, kXIButtonMap[b].mapped,
+                              true);
+    } else if (!(state.Gamepad.wButtons & kXIButtonMap[b].button) &&
+               gamepad.state.Gamepad.wButtons & kXIButtonMap[b].button) {
+      // Button released
+      service->NewButtonEvent(gamepad.gamepadHandle, kXIButtonMap[b].mapped,
+                              false);
+    }
+  }
+
+  // Then triggers
+  if (state.Gamepad.bLeftTrigger != gamepad.state.Gamepad.bLeftTrigger) {
+    const bool pressed =
+        state.Gamepad.bLeftTrigger >= XINPUT_GAMEPAD_TRIGGER_THRESHOLD;
+    service->NewButtonEvent(gamepad.gamepadHandle, kButtonLeftTrigger, pressed,
+                            state.Gamepad.bLeftTrigger / 255.0);
+  }
+  if (state.Gamepad.bRightTrigger != gamepad.state.Gamepad.bRightTrigger) {
+    const bool pressed =
+        state.Gamepad.bRightTrigger >= XINPUT_GAMEPAD_TRIGGER_THRESHOLD;
+    service->NewButtonEvent(gamepad.gamepadHandle, kButtonRightTrigger, pressed,
+                            state.Gamepad.bRightTrigger / 255.0);
+  }
+
+  // Finally deal with analog sticks
+  // TODO: bug 1001955 - Support deadzones.
+  if (state.Gamepad.sThumbLX != gamepad.state.Gamepad.sThumbLX) {
+    const float div = state.Gamepad.sThumbLX > 0 ? 32767.0 : 32768.0;
+    service->NewAxisMoveEvent(gamepad.gamepadHandle, kLeftStickXAxis,
+                              state.Gamepad.sThumbLX / div);
+  }
+  if (state.Gamepad.sThumbLY != gamepad.state.Gamepad.sThumbLY) {
+    const float div = state.Gamepad.sThumbLY > 0 ? 32767.0 : 32768.0;
+    service->NewAxisMoveEvent(gamepad.gamepadHandle, kLeftStickYAxis,
+                              -1.0 * state.Gamepad.sThumbLY / div);
+  }
+  if (state.Gamepad.sThumbRX != gamepad.state.Gamepad.sThumbRX) {
+    const float div = state.Gamepad.sThumbRX > 0 ? 32767.0 : 32768.0;
+    service->NewAxisMoveEvent(gamepad.gamepadHandle, kRightStickXAxis,
+                              state.Gamepad.sThumbRX / div);
+  }
+  if (state.Gamepad.sThumbRY != gamepad.state.Gamepad.sThumbRY) {
+    const float div = state.Gamepad.sThumbRY > 0 ? 32767.0 : 32768.0;
+    service->NewAxisMoveEvent(gamepad.gamepadHandle, kRightStickYAxis,
+                              -1.0 * state.Gamepad.sThumbRY / div);
+  }
+  gamepad.state = state;
+}
+
+// Used to sort a list of axes by HID usage.
+class HidValueComparator {
+ public:
+  bool Equals(const Gamepad::axisValue& c1,
+              const Gamepad::axisValue& c2) const {
+    return c1.caps.UsagePage == c2.caps.UsagePage &&
+           c1.caps.Range.UsageMin == c2.caps.Range.UsageMin;
+  }
+  bool LessThan(const Gamepad::axisValue& c1,
+                const Gamepad::axisValue& c2) const {
+    if (c1.caps.UsagePage == c2.caps.UsagePage) {
+      return c1.caps.Range.UsageMin < c2.caps.Range.UsageMin;
+    }
+    return c1.caps.UsagePage < c2.caps.UsagePage;
+  }
+};
+
+// GetRawGamepad() processes its raw data from HID and
+// then trying to remapping buttons and axes based on
+// the mapping rules that are defined for different gamepad products.
+bool WindowsGamepadService::GetRawGamepad(HANDLE handle) {
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  if (!service) {
+    return true;
+  }
+
+  if (!mHID) {
+    return false;
+  }
+
+  for (unsigned i = 0; i < mGamepads.Length(); i++) {
+    if (mGamepads[i].type == kRawInputGamepad &&
+        mGamepads[i].handle == handle) {
+      mGamepads[i].present = true;
+      return true;
+    }
+  }
+
+  RID_DEVICE_INFO rdi = {};
+  UINT size = rdi.cbSize = sizeof(RID_DEVICE_INFO);
+  if (GetRawInputDeviceInfo(handle, RIDI_DEVICEINFO, &rdi, &size) ==
+      kRawInputError) {
+    return false;
+  }
+  // Ensure that this is a device we care about
+  if (!SupportedUsage(rdi.hid.usUsagePage, rdi.hid.usUsage)) {
+    return false;
+  }
+
+  // Device name is a mostly-opaque string.
+  if (GetRawInputDeviceInfo(handle, RIDI_DEVICENAME, nullptr, &size) ==
+      kRawInputError) {
+    return false;
+  }
+
+  nsTArray<wchar_t> devname(size);
+  devname.SetLength(size);
+  if (GetRawInputDeviceInfo(handle, RIDI_DEVICENAME, devname.Elements(),
+                            &size) == kRawInputError) {
+    return false;
+  }
+
+  // Per http://msdn.microsoft.com/en-us/library/windows/desktop/ee417014.aspx
+  // device names containing "IG_" are XInput controllers. Ignore those
+  // devices since we'll handle them with XInput.
+  if (wcsstr(devname.Elements(), L"IG_")) {
+    return false;
+  }
+
+  // Product string is a human-readable name.
+  // Per
+  // http://msdn.microsoft.com/en-us/library/windows/hardware/ff539681%28v=vs.85%29.aspx
+  // "For USB devices, the maximum string length is 126 wide characters (not
+  // including the terminating NULL character)."
+  wchar_t name[128] = {0};
+  size = sizeof(name);
+  nsTArray<char> gamepad_name;
+  // Creating this file with FILE_FLAG_OVERLAPPED to perform
+  // an asynchronous request in WriteOutputReport.
+  mHidHandle.own(CreateFile(devname.Elements(), GENERIC_READ | GENERIC_WRITE,
+                            FILE_SHARE_READ | FILE_SHARE_WRITE, nullptr,
+                            OPEN_EXISTING, FILE_FLAG_OVERLAPPED, nullptr));
+  if (mHidHandle != INVALID_HANDLE_VALUE) {
+    if (mHID.mHidD_GetProductString(mHidHandle, &name, size)) {
+      int bytes = WideCharToMultiByte(CP_UTF8, 0, name, -1, nullptr, 0, nullptr,
+                                      nullptr);
+      gamepad_name.SetLength(bytes);
+      WideCharToMultiByte(CP_UTF8, 0, name, -1, gamepad_name.Elements(), bytes,
+                          nullptr, nullptr);
+    }
+  }
+  if (gamepad_name.Length() == 0 || !gamepad_name[0]) {
+    const char kUnknown[] = "Unknown Gamepad";
+    gamepad_name.SetLength(ArrayLength(kUnknown));
+    strcpy_s(gamepad_name.Elements(), gamepad_name.Length(), kUnknown);
+  }
+
+  char gamepad_id[256] = {0};
+  _snprintf_s(gamepad_id, _TRUNCATE, "%04x-%04x-%s", rdi.hid.dwVendorId,
+              rdi.hid.dwProductId, gamepad_name.Elements());
+
+  nsTArray<uint8_t> preparsedbytes;
+  if (!GetPreparsedData(handle, preparsedbytes)) {
+    return false;
+  }
+
+  PHIDP_PREPARSED_DATA parsed =
+      reinterpret_cast<PHIDP_PREPARSED_DATA>(preparsedbytes.Elements());
+  HIDP_CAPS caps;
+  if (mHID.mHidP_GetCaps(parsed, &caps) != HIDP_STATUS_SUCCESS) {
+    return false;
+  }
+
+  // Enumerate buttons.
+  USHORT count = caps.NumberInputButtonCaps;
+  nsTArray<HIDP_BUTTON_CAPS> buttonCaps(count);
+  buttonCaps.SetLength(count);
+  if (mHID.mHidP_GetButtonCaps(HidP_Input, buttonCaps.Elements(), &count,
+                               parsed) != HIDP_STATUS_SUCCESS) {
+    return false;
+  }
+  uint32_t numButtons = 0;
+  for (unsigned i = 0; i < count; i++) {
+    // Each buttonCaps is typically a range of buttons.
+    numButtons +=
+        buttonCaps[i].Range.UsageMax - buttonCaps[i].Range.UsageMin + 1;
+  }
+
+  // Enumerate value caps, which represent axes and d-pads.
+  count = caps.NumberInputValueCaps;
+  nsTArray<HIDP_VALUE_CAPS> axisCaps(count);
+  axisCaps.SetLength(count);
+  if (mHID.mHidP_GetValueCaps(HidP_Input, axisCaps.Elements(), &count,
+                              parsed) != HIDP_STATUS_SUCCESS) {
+    return false;
+  }
+
+  size_t numAxes = 0;
+  nsTArray<Gamepad::axisValue> axes(kAxesLengthCap);
+  // We store these value caps and handle the dpad info in GamepadRemapper
+  // later.
+  axes.SetLength(kAxesLengthCap);
+
+  // Looking for the exisiting ramapping rule.
+  bool defaultRemapper = false;
+  RefPtr<GamepadRemapper> remapper = GetGamepadRemapper(
+      rdi.hid.dwVendorId, rdi.hid.dwProductId, defaultRemapper);
+  MOZ_ASSERT(remapper);
+
+  for (size_t i = 0; i < count; i++) {
+    const size_t axisIndex =
+        axisCaps[i].Range.UsageMin - kAxisMinimumUsageNumber;
+    if (axisIndex < kAxesLengthCap && !axes[axisIndex].active) {
+      axes[axisIndex].caps = axisCaps[i];
+      axes[axisIndex].active = true;
+      numAxes = std::max(numAxes, axisIndex + 1);
+    }
+  }
+
+  // Not already present, add it.
+
+  remapper->SetAxisCount(numAxes);
+  remapper->SetButtonCount(numButtons);
+  Gamepad gamepad(numAxes, numButtons, kRawInputGamepad);
+  gamepad.handle = handle;
+
+  for (unsigned i = 0; i < gamepad.numAxes; i++) {
+    gamepad.axes[i] = axes[i];
+  }
+
+  gamepad.remapper = remapper.forget();
+  // TODO: Bug 680289, implement gamepad haptics for Windows.
+  gamepad.gamepadHandle = service->AddGamepad(
+      gamepad_id, gamepad.remapper->GetMappingType(), GamepadHand::_empty,
+      gamepad.remapper->GetButtonCount(), gamepad.remapper->GetAxisCount(), 0,
+      gamepad.remapper->GetLightIndicatorCount(),
+      gamepad.remapper->GetTouchEventCount());
+
+  nsTArray<GamepadLightIndicatorType> lightTypes;
+  gamepad.remapper->GetLightIndicators(lightTypes);
+  for (uint32_t i = 0; i < lightTypes.Length(); ++i) {
+    if (lightTypes[i] != GamepadLightIndicator::DefaultType()) {
+      service->NewLightIndicatorTypeEvent(gamepad.gamepadHandle, i,
+                                          lightTypes[i]);
+    }
+  }
+
+  mGamepads.AppendElement(std::move(gamepad));
+  return true;
+}
+
+bool WindowsGamepadService::HandleRawInput(HRAWINPUT handle) {
+  if (!mHID) {
+    return false;
+  }
+
+  RefPtr<GamepadPlatformService> service =
+      GamepadPlatformService::GetParentService();
+  if (!service) {
+    return false;
+  }
+
+  // First, get data from the handle
+  UINT size;
+  GetRawInputData(handle, RID_INPUT, nullptr, &size, sizeof(RAWINPUTHEADER));
+  nsTArray<uint8_t> data(size);
+  data.SetLength(size);
+  if (GetRawInputData(handle, RID_INPUT, data.Elements(), &size,
+                      sizeof(RAWINPUTHEADER)) == kRawInputError) {
+    return false;
+  }
+  PRAWINPUT raw = reinterpret_cast<PRAWINPUT>(data.Elements());
+
+  Gamepad* gamepad = nullptr;
+  for (unsigned i = 0; i < mGamepads.Length(); i++) {
+    if (mGamepads[i].type == kRawInputGamepad &&
+        mGamepads[i].handle == raw->header.hDevice) {
+      gamepad = &mGamepads[i];
+      break;
+    }
+  }
+  if (gamepad == nullptr) {
+    return false;
+  }
+
+  // Second, get the preparsed data
+  nsTArray<uint8_t> parsedbytes;
+  if (!GetPreparsedData(raw->header.hDevice, parsedbytes)) {
+    return false;
+  }
+  PHIDP_PREPARSED_DATA parsed =
+      reinterpret_cast<PHIDP_PREPARSED_DATA>(parsedbytes.Elements());
+
+  // Get all the pressed buttons.
+  nsTArray<USAGE> usages(gamepad->numButtons);
+  usages.SetLength(gamepad->numButtons);
+  ULONG usageLength = gamepad->numButtons;
+  if (mHID.mHidP_GetUsages(HidP_Input, kButtonUsagePage, 0, usages.Elements(),
+                           &usageLength, parsed, (PCHAR)raw->data.hid.bRawData,
+                           raw->data.hid.dwSizeHid) != HIDP_STATUS_SUCCESS) {
+    return false;
+  }
+
+  nsTArray<bool> buttons(gamepad->numButtons);
+  buttons.SetLength(gamepad->numButtons);
+  // If we don't zero out the buttons array first, sometimes it can reuse
+  // values.
+  memset(buttons.Elements(), 0, gamepad->numButtons * sizeof(bool));
+
+  for (unsigned i = 0; i < usageLength; i++) {
+    // The button index in usages may be larger than what we detected when
+    // enumerating gamepads. If so, warn and continue.
+    //
+    // Usage ID of 0 is reserved, so it should always be 1 or higher.
+    if (NS_WARN_IF((usages[i] - 1u) >= buttons.Length())) {
+      continue;
+    }
+    buttons[usages[i] - 1u] = true;
+  }
+
+  for (unsigned i = 0; i < gamepad->numButtons; i++) {
+    if (gamepad->buttons[i] != buttons[i]) {
+      gamepad->remapper->RemapButtonEvent(gamepad->gamepadHandle, i,
+                                          buttons[i]);
+      gamepad->buttons[i] = buttons[i];
+    }
+  }
+
+  // Get all axis values.
+  for (unsigned i = 0; i < gamepad->numAxes; i++) {
+    double new_value;
+    if (gamepad->axes[i].caps.LogicalMin < 0) {
+      LONG value;
+      if (mHID.mHidP_GetScaledUsageValue(
+              HidP_Input, gamepad->axes[i].caps.UsagePage, 0,
+              gamepad->axes[i].caps.Range.UsageMin, &value, parsed,
+              (PCHAR)raw->data.hid.bRawData,
+              raw->data.hid.dwSizeHid) != HIDP_STATUS_SUCCESS) {
+        continue;
+      }
+      new_value = ScaleAxis(value, gamepad->axes[i].caps.LogicalMin,
+                            gamepad->axes[i].caps.LogicalMax);
+    } else {
+      ULONG value;
+      if (mHID.mHidP_GetUsageValue(
+              HidP_Input, gamepad->axes[i].caps.UsagePage, 0,
+              gamepad->axes[i].caps.Range.UsageMin, &value, parsed,
+              (PCHAR)raw->data.hid.bRawData,
+              raw->data.hid.dwSizeHid) != HIDP_STATUS_SUCCESS) {
+        continue;
+      }
+
+      new_value = ScaleAxis(value, gamepad->axes[i].caps.LogicalMin,
+                            gamepad->axes[i].caps.LogicalMax);
+    }
+    if (gamepad->axes[i].value != new_value) {
+      gamepad->remapper->RemapAxisMoveEvent(gamepad->gamepadHandle, i,
+                                            new_value);
+      gamepad->axes[i].value = new_value;
+    }
+  }
+
+  BYTE* rawData = raw->data.hid.bRawData;
+  gamepad->remapper->ProcessTouchData(gamepad->gamepadHandle, rawData);
+
+  return true;
+}
+
+void WindowsGamepadService::SetLightIndicatorColor(
+    const Tainted<GamepadHandle>& aGamepadHandle,
+    const Tainted<uint32_t>& aLightColorIndex, const uint8_t& aRed,
+    const uint8_t& aGreen, const uint8_t& aBlue) {
+  // We get aControllerIdx from GamepadPlatformService::AddGamepad(),
+  // It begins from 1 and is stored at Gamepad.id.
+  const Gamepad* gamepad = (MOZ_FIND_AND_VALIDATE(
+      aGamepadHandle, list_item.gamepadHandle == aGamepadHandle, mGamepads));
+  if (!gamepad) {
+    MOZ_ASSERT(false);
+    return;
+  }
+
+  RefPtr<GamepadRemapper> remapper = gamepad->remapper;
+  if (!remapper ||
+      MOZ_IS_VALID(aLightColorIndex,
+                   remapper->GetLightIndicatorCount() <= aLightColorIndex)) {
+    MOZ_ASSERT(false);
+    return;
+  }
+
+  std::vector<uint8_t> report;
+  remapper->GetLightColorReport(aRed, aGreen, aBlue, report);
+  WriteOutputReport(report);
+}
+
+size_t WindowsGamepadService::WriteOutputReport(
+    const std::vector<uint8_t>& aReport) {
+  DCHECK(static_cast<const void*>(aReport.data()));
+  DCHECK_GE(aReport.size(), 1U);
+  if (!mHidHandle) return 0;
+
+  nsAutoHandle eventHandle(::CreateEvent(nullptr, FALSE, FALSE, nullptr));
+  OVERLAPPED overlapped = {0};
+  overlapped.hEvent = eventHandle;
+
+  // Doing an asynchronous write to allows us to time out
+  // if the write takes too long.
+  DWORD bytesWritten = 0;
+  BOOL writeSuccess =
+      ::WriteFile(mHidHandle, static_cast<const void*>(aReport.data()),
+                  aReport.size(), &bytesWritten, &overlapped);
+  if (!writeSuccess) {
+    DWORD error = ::GetLastError();
+    if (error == ERROR_IO_PENDING) {
+      // Wait for the write to complete. This causes WriteOutputReport to behave
+      // synchronously but with a timeout.
+      DWORD wait_object = ::WaitForSingleObject(overlapped.hEvent, 100);
+      if (wait_object == WAIT_OBJECT_0) {
+        if (!::GetOverlappedResult(mHidHandle, &overlapped, &bytesWritten,
+                                   TRUE)) {
+          return 0;
+        }
+      } else {
+        // Wait failed, or the timeout was exceeded before the write completed.
+        // Cancel the write request.
+        if (::CancelIo(mHidHandle)) {
+          wait_object = ::WaitForSingleObject(overlapped.hEvent, INFINITE);
+          MOZ_ASSERT(wait_object == WAIT_OBJECT_0);
+        }
+      }
+    }
+  }
+  return writeSuccess ? bytesWritten : 0;
+}
+
+void WindowsGamepadService::Startup() { ScanForDevices(); }
+
+void WindowsGamepadService::Shutdown() { Cleanup(); }
+
+void WindowsGamepadService::Cleanup() {
+  mIsXInputMonitoring = false;
+  if (mDirectInputTimer) {
+    mDirectInputTimer->Cancel();
+  }
+  if (mXInputTimer) {
+    mXInputTimer->Cancel();
+  }
+  if (mDeviceChangeTimer) {
+    mDeviceChangeTimer->Cancel();
+  }
+
+  mGamepads.Clear();
+}
+
+void WindowsGamepadService::DevicesChanged(bool aIsStablizing) {
+  if (aIsStablizing) {
+    mDeviceChangeTimer->Cancel();
+    mDeviceChangeTimer->InitWithNamedFuncCallback(
+        DevicesChangeCallback, this, kDevicesChangedStableDelay,
+        nsITimer::TYPE_ONE_SHOT, "DevicesChangeCallback");
+  } else {
+    ScanForDevices();
+  }
+}
+
+bool RegisterRawInput(HWND hwnd, bool enable) {
+  nsTArray<RAWINPUTDEVICE> rid(ArrayLength(kUsagePages));
+  rid.SetLength(ArrayLength(kUsagePages));
+
+  for (unsigned i = 0; i < rid.Length(); i++) {
+    rid[i].usUsagePage = kUsagePages[i].usagePage;
+    rid[i].usUsage = kUsagePages[i].usage;
+    rid[i].dwFlags =
+        enable ? RIDEV_EXINPUTSINK | RIDEV_DEVNOTIFY : RIDEV_REMOVE;
+    rid[i].hwndTarget = hwnd;
+  }
+
+  if (!RegisterRawInputDevices(rid.Elements(), rid.Length(),
+                               sizeof(RAWINPUTDEVICE))) {
+    return false;
+  }
+  return true;
+}
+
+static LRESULT CALLBACK GamepadWindowProc(HWND hwnd, UINT msg, WPARAM wParam,
+                                          LPARAM lParam) {
+  const unsigned int DBT_DEVICEARRIVAL = 0x8000;
+  const unsigned int DBT_DEVICEREMOVECOMPLETE = 0x8004;
+  const unsigned int DBT_DEVNODES_CHANGED = 0x7;
+
+  switch (msg) {
+    case WM_DEVICECHANGE:
+      if (wParam == DBT_DEVICEARRIVAL || wParam == DBT_DEVICEREMOVECOMPLETE ||
+          wParam == DBT_DEVNODES_CHANGED) {
+        if (gService) {
+          gService->DevicesChanged(true);
+        }
+      }
+      break;
+    case WM_INPUT:
+      if (gService) {
+        gService->HandleRawInput(reinterpret_cast<HRAWINPUT>(lParam));
+      }
+      break;
+  }
+  return DefWindowProc(hwnd, msg, wParam, lParam);
+}
+
+class StartWindowsGamepadServiceRunnable final : public Runnable {
+ public:
+  StartWindowsGamepadServiceRunnable()
+      : Runnable("StartWindowsGamepadServiceRunnable") {}
+
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT(NS_GetCurrentThread() == gMonitorThread);
+    gService = new WindowsGamepadService();
+    gService->Startup();
+
+    if (sHWnd == nullptr) {
+      WNDCLASSW wc;
+      HMODULE hSelf = GetModuleHandle(nullptr);
+
+      if (!GetClassInfoW(hSelf, L"MozillaGamepadClass", &wc)) {
+        ZeroMemory(&wc, sizeof(WNDCLASSW));
+        wc.hInstance = hSelf;
+        wc.lpfnWndProc = GamepadWindowProc;
+        wc.lpszClassName = L"MozillaGamepadClass";
+        RegisterClassW(&wc);
+      }
+
+      sHWnd = CreateWindowW(L"MozillaGamepadClass", L"Gamepad Watcher", 0, 0, 0,
+                            0, 0, nullptr, nullptr, hSelf, nullptr);
+      RegisterRawInput(sHWnd, true);
+    }
+
+    // Explicitly start the message loop
+    gService->StartMessageLoop();
+
+    return NS_OK;
+  }
+
+ private:
+  ~StartWindowsGamepadServiceRunnable() {}
+};
+
+class StopWindowsGamepadServiceRunnable final : public Runnable {
+ public:
+  StopWindowsGamepadServiceRunnable()
+      : Runnable("StopWindowsGamepadServiceRunnable") {}
+
+  NS_IMETHOD Run() override {
+    MOZ_ASSERT(NS_GetCurrentThread() == gMonitorThread);
+    if (sHWnd) {
+      RegisterRawInput(sHWnd, false);
+      DestroyWindow(sHWnd);
+      sHWnd = nullptr;
+    }
+
+    gService->Shutdown();
+    delete gService;
+    gService = nullptr;
+
+    return NS_OK;
+  }
+
+ private:
+  ~StopWindowsGamepadServiceRunnable() {}
+};
+
+}  // namespace
+
+namespace mozilla::dom {
+
+using namespace mozilla::ipc;
+
+void StartGamepadMonitoring() {
+  AssertIsOnBackgroundThread();
+
+  if (gMonitorThread || gService) {
+    return;
+  }
+  sIsShutdown = false;
+  NS_NewNamedThread("Gamepad", getter_AddRefs(gMonitorThread));
+  gMonitorThread->Dispatch(new StartWindowsGamepadServiceRunnable(),
+                           NS_DISPATCH_NORMAL);
+}
+
+void StopGamepadMonitoring() {
+  AssertIsOnBackgroundThread();
+
+  if (sIsShutdown) {
+    return;
+  }
+  sIsShutdown = true;
+  gMonitorThread->Dispatch(new StopWindowsGamepadServiceRunnable(),
+                           NS_DISPATCH_NORMAL);
+  gMonitorThread->Shutdown();
+  gMonitorThread = nullptr;
+}
+
+void SetGamepadLightIndicatorColor(const Tainted<GamepadHandle>& aGamepadHandle,
+                                   const Tainted<uint32_t>& aLightColorIndex,
+                                   const uint8_t& aRed, const uint8_t& aGreen,
+                                   const uint8_t& aBlue) {
+  MOZ_ASSERT(gService);
+  if (!gService) {
+    return;
+  }
+  gService->SetLightIndicatorColor(aGamepadHandle, aLightColorIndex, aRed,
+                                   aGreen, aBlue);
+}
+
+}  // namespace mozilla::dom