deleted file mode 100644
--- a/hal/android/AndroidAlarm.cpp
+++ /dev/null
@@ -1,48 +0,0 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include "Hal.h"
-
-#include "GeneratedJNINatives.h"
-#include "GeneratedJNIWrappers.h"
-
-using namespace mozilla::hal;
-
-namespace mozilla {
-
-class AlarmReceiver : public java::AlarmReceiver::Natives<AlarmReceiver>
-{
-private:
-    AlarmReceiver();
-
-public:
-    static void NotifyAlarmFired() {
-        hal::NotifyAlarmFired();
-    }
-};
-
-namespace hal_impl {
-
-bool
-EnableAlarm()
-{
-    AlarmReceiver::Init();
-    return true;
-}
-
-void
-DisableAlarm()
-{
-    java::GeckoAppShell::DisableAlarm();
-}
-
-bool
-SetAlarm(int32_t aSeconds, int32_t aNanoseconds)
-{
-    return java::GeckoAppShell::SetAlarm(aSeconds, aNanoseconds);
-}
-
-} // hal_impl
-} // mozilla

--- a/hal/moz.build
+++ b/hal/moz.build
@@ -38,18 +38,18 @@ SOURCES += [
     'Hal.cpp',
 ]
 
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'android':
     LOCAL_INCLUDES += [
         '/widget/android',
     ]
     UNIFIED_SOURCES += [
-        'android/AndroidAlarm.cpp',
         'android/AndroidSensor.cpp',
+        'fallback/FallbackAlarm.cpp',
         'fallback/FallbackPower.cpp',
         'linux/LinuxMemory.cpp',
     ]
     # AndroidHal.cpp cannot be built in unified mode because it relies on HalImpl.h.
     SOURCES += [
         'android/AndroidHal.cpp',
     ]
 elif CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gonk':

--- a/mobile/android/base/AndroidManifest.xml.in
+++ b/mobile/android/base/AndroidManifest.xml.in
@@ -232,19 +232,16 @@
                  android:exported="false"
                  android:process="@MANGLED_ANDROID_PACKAGE_NAME@.Restarter">
         </service>
 
         <service android:name="org.mozilla.gecko.media.MediaControlService"
                  android:exported="false">
         </service>
 
-        <receiver android:name="org.mozilla.gecko.AlarmReceiver" >
-        </receiver>
-
         <receiver
             android:name="org.mozilla.gecko.notifications.WhatsNewReceiver"
             android:exported="false">
             <intent-filter>
                 <action android:name="android.intent.action.PACKAGE_REPLACED" />
                 <data android:scheme="package" android:path="org.mozilla.gecko" />
             </intent-filter>
         </receiver>

--- a/mobile/android/base/moz.build
+++ b/mobile/android/base/moz.build
@@ -230,17 +230,16 @@ if CONFIG['MOZ_WEBRTC']:
         'gecko-view.jar',
     ]
     wrjar.javac_flags += ['-Xlint:all,-deprecation,-cast']
 
 gvjar = add_java_jar('gecko-view')
 
 gvjar.sources += [geckoview_source_dir + 'java/org/mozilla/gecko/' + x
                   for x in [
-    'AlarmReceiver.java',
     'AndroidGamepadManager.java',
     'BaseGeckoInterface.java',
     'Clipboard.java',
     'ContextGetter.java',
     'CrashHandler.java',
     'EventDispatcher.java',
     'GeckoAccessibility.java',
     'GeckoAppShell.java',

deleted file mode 100644
--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/AlarmReceiver.java
+++ /dev/null
@@ -1,42 +0,0 @@
-/* -*- Mode: Java; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: nil; -*-
- * 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/. */
-
-package org.mozilla.gecko;
-
-import org.mozilla.gecko.annotation.WrapForJNI;
-
-import android.app.IntentService;
-import android.content.Context;
-import android.content.Intent;
-import android.content.BroadcastReceiver;
-import android.os.PowerManager;
-import android.os.PowerManager.WakeLock;
-import android.util.Log;
-
-import java.util.Timer;
-import java.util.TimerTask;
-
-public class AlarmReceiver extends BroadcastReceiver {
-    @Override
-    public void onReceive(Context context, Intent intent) {
-        PowerManager powerManager = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
-        final WakeLock wakeLock = powerManager.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP, "GeckoAlarm");
-        wakeLock.acquire();
-
-        AlarmReceiver.notifyAlarmFired();
-        TimerTask releaseLockTask = new TimerTask() {
-            @Override
-            public void run() {
-                wakeLock.release();
-            }
-        };
-        Timer timer = new Timer();
-        // 5 seconds ought to be enough for anybody
-        timer.schedule(releaseLockTask, 5 * 1000);
-    }
-
-    @WrapForJNI(calledFrom = "ui", dispatchTo = "gecko")
-    private static native void notifyAlarmFired();
-}

--- a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/GeckoAppShell.java
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/GeckoAppShell.java
@@ -39,18 +39,16 @@ import org.mozilla.gecko.util.EventCallb
 import org.mozilla.gecko.util.HardwareCodecCapabilityUtils;
 import org.mozilla.gecko.util.HardwareUtils;
 import org.mozilla.gecko.util.ProxySelector;
 import org.mozilla.gecko.util.ThreadUtils;
 
 import android.Manifest;
 import android.app.Activity;
 import android.app.ActivityManager;
-import android.app.AlarmManager;
-import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.pm.ActivityInfo;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.PackageManager.NameNotFoundException;
@@ -391,44 +389,16 @@ public class GeckoAppShell
         }
     }
 
     @WrapForJNI(calledFrom = "gecko")
     private static void enableLocationHighAccuracy(final boolean enable) {
         locationHighAccuracyEnabled = enable;
     }
 
-    @WrapForJNI(calledFrom = "gecko")
-    private static boolean setAlarm(int aSeconds, int aNanoSeconds) {
-        AlarmManager am = (AlarmManager)
-            getApplicationContext().getSystemService(Context.ALARM_SERVICE);
-
-        Intent intent = new Intent(getApplicationContext(), AlarmReceiver.class);
-        PendingIntent pi = PendingIntent.getBroadcast(
-                getApplicationContext(), 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
-
-        // AlarmManager only supports millisecond precision
-        long time = ((long) aSeconds * 1000) + ((long) aNanoSeconds / 1_000_000L);
-        am.setExact(AlarmManager.RTC_WAKEUP, time, pi);
-
-        return true;
-    }
-
-    @WrapForJNI(calledFrom = "gecko")
-    private static void disableAlarm() {
-        AlarmManager am = (AlarmManager)
-            getApplicationContext().getSystemService(Context.ALARM_SERVICE);
-
-        Intent intent = new Intent(getApplicationContext(), AlarmReceiver.class);
-        PendingIntent pi = PendingIntent.getBroadcast(
-                getApplicationContext(), 0, intent,
-                PendingIntent.FLAG_UPDATE_CURRENT);
-        am.cancel(pi);
-    }
-
     @WrapForJNI(calledFrom = "ui", dispatchTo = "gecko")
     /* package */ static native void onSensorChanged(int hal_type, float x, float y, float z,
                                                      float w, int accuracy, long time);
 
     @WrapForJNI(calledFrom = "ui", dispatchTo = "gecko")
     /* package */ static native void onLocationChanged(double latitude, double longitude,
                                                        double altitude, float accuracy,
                                                        float bearing, float speed, long time);

--- a/widget/android/GeneratedJNINatives.h
+++ b/widget/android/GeneratedJNINatives.h
@@ -9,31 +9,16 @@
 
 #include "GeneratedJNIWrappers.h"
 #include "mozilla/jni/Natives.h"
 
 namespace mozilla {
 namespace java {
 
 template<class Impl>
-class AlarmReceiver::Natives : public mozilla::jni::NativeImpl<AlarmReceiver, Impl>
-{
-public:
-    static const JNINativeMethod methods[1];
-};
-
-template<class Impl>
-const JNINativeMethod AlarmReceiver::Natives<Impl>::methods[] = {
-
-    mozilla::jni::MakeNativeMethod<AlarmReceiver::NotifyAlarmFired_t>(
-            mozilla::jni::NativeStub<AlarmReceiver::NotifyAlarmFired_t, Impl>
-            ::template Wrap<&Impl::NotifyAlarmFired>)
-};
-
-template<class Impl>
 class AndroidGamepadManager::Natives : public mozilla::jni::NativeImpl<AndroidGamepadManager, Impl>
 {
 public:
     static const JNINativeMethod methods[3];
 };
 
 template<class Impl>
 const JNINativeMethod AndroidGamepadManager::Natives<Impl>::methods[] = {

--- a/widget/android/GeneratedJNIWrappers.cpp
+++ b/widget/android/GeneratedJNIWrappers.cpp
@@ -5,22 +5,16 @@
 // will cause your build to fail.
 
 #include "GeneratedJNIWrappers.h"
 #include "mozilla/jni/Accessors.h"
 
 namespace mozilla {
 namespace java {
 
-const char AlarmReceiver::name[] =
-        "org/mozilla/gecko/AlarmReceiver";
-
-constexpr char AlarmReceiver::NotifyAlarmFired_t::name[];
-constexpr char AlarmReceiver::NotifyAlarmFired_t::signature[];
-
 const char AndroidGamepadManager::name[] =
         "org/mozilla/gecko/AndroidGamepadManager";
 
 constexpr char AndroidGamepadManager::OnAxisChange_t::name[];
 constexpr char AndroidGamepadManager::OnAxisChange_t::signature[];
 
 constexpr char AndroidGamepadManager::OnButtonChange_t::name[];
 constexpr char AndroidGamepadManager::OnButtonChange_t::signature[];
@@ -170,24 +164,16 @@ auto GeckoAppShell::CreateInputStream(mo
 constexpr char GeckoAppShell::CreateShortcut_t::name[];
 constexpr char GeckoAppShell::CreateShortcut_t::signature[];
 
 auto GeckoAppShell::CreateShortcut(mozilla::jni::String::Param a0, mozilla::jni::String::Param a1) -> void
 {
     return mozilla::jni::Method<CreateShortcut_t>::Call(GeckoAppShell::Context(), nullptr, a0, a1);
 }
 
-constexpr char GeckoAppShell::DisableAlarm_t::name[];
-constexpr char GeckoAppShell::DisableAlarm_t::signature[];
-
-auto GeckoAppShell::DisableAlarm() -> void
-{
-    return mozilla::jni::Method<DisableAlarm_t>::Call(GeckoAppShell::Context(), nullptr);
-}
-
 constexpr char GeckoAppShell::DisableBatteryNotifications_t::name[];
 constexpr char GeckoAppShell::DisableBatteryNotifications_t::signature[];
 
 auto GeckoAppShell::DisableBatteryNotifications() -> void
 {
     return mozilla::jni::Method<DisableBatteryNotifications_t>::Call(GeckoAppShell::Context(), nullptr);
 }
 
@@ -607,24 +593,16 @@ constexpr char GeckoAppShell::ReportJava
 constexpr char GeckoAppShell::ScheduleRestart_t::name[];
 constexpr char GeckoAppShell::ScheduleRestart_t::signature[];
 
 auto GeckoAppShell::ScheduleRestart() -> void
 {
     return mozilla::jni::Method<ScheduleRestart_t>::Call(GeckoAppShell::Context(), nullptr);
 }
 
-constexpr char GeckoAppShell::SetAlarm_t::name[];
-constexpr char GeckoAppShell::SetAlarm_t::signature[];
-
-auto GeckoAppShell::SetAlarm(int32_t a0, int32_t a1) -> bool
-{
-    return mozilla::jni::Method<SetAlarm_t>::Call(GeckoAppShell::Context(), nullptr, a0, a1);
-}
-
 constexpr char GeckoAppShell::SetFullScreen_t::name[];
 constexpr char GeckoAppShell::SetFullScreen_t::signature[];
 
 auto GeckoAppShell::SetFullScreen(bool a0) -> void
 {
     return mozilla::jni::Method<SetFullScreen_t>::Call(GeckoAppShell::Context(), nullptr, a0);
 }
 

--- a/widget/android/GeneratedJNIWrappers.h
+++ b/widget/android/GeneratedJNIWrappers.h
@@ -7,46 +7,16 @@
 #ifndef GeneratedJNIWrappers_h
 #define GeneratedJNIWrappers_h
 
 #include "mozilla/jni/Refs.h"
 
 namespace mozilla {
 namespace java {
 
-class AlarmReceiver : public mozilla::jni::ObjectBase<AlarmReceiver>
-{
-public:
-    static const char name[];
-
-    explicit AlarmReceiver(const Context& ctx) : ObjectBase<AlarmReceiver>(ctx) {}
-
-    struct NotifyAlarmFired_t {
-        typedef AlarmReceiver Owner;
-        typedef void ReturnType;
-        typedef void SetterType;
-        typedef mozilla::jni::Args<> Args;
-        static constexpr char name[] = "notifyAlarmFired";
-        static constexpr char signature[] =
-                "()V";
-        static const bool isStatic = true;
-        static const mozilla::jni::ExceptionMode exceptionMode =
-                mozilla::jni::ExceptionMode::ABORT;
-        static const mozilla::jni::CallingThread callingThread =
-                mozilla::jni::CallingThread::UI;
-        static const mozilla::jni::DispatchTarget dispatchTarget =
-                mozilla::jni::DispatchTarget::GECKO;
-    };
-
-    static const mozilla::jni::CallingThread callingThread =
-            mozilla::jni::CallingThread::UI;
-
-    template<class Impl> class Natives;
-};
-
 class AndroidGamepadManager : public mozilla::jni::ObjectBase<AndroidGamepadManager>
 {
 public:
     static const char name[];
 
     explicit AndroidGamepadManager(const Context& ctx) : ObjectBase<AndroidGamepadManager>(ctx) {}
 
     struct OnAxisChange_t {
@@ -559,35 +529,16 @@ public:
         static const mozilla::jni::CallingThread callingThread =
                 mozilla::jni::CallingThread::GECKO;
         static const mozilla::jni::DispatchTarget dispatchTarget =
                 mozilla::jni::DispatchTarget::CURRENT;
     };
 
     static auto CreateShortcut(mozilla::jni::String::Param, mozilla::jni::String::Param) -> void;
 
-    struct DisableAlarm_t {
-        typedef GeckoAppShell Owner;
-        typedef void ReturnType;
-        typedef void SetterType;
-        typedef mozilla::jni::Args<> Args;
-        static constexpr char name[] = "disableAlarm";
-        static constexpr char signature[] =
-                "()V";
-        static const bool isStatic = true;
-        static const mozilla::jni::ExceptionMode exceptionMode =
-                mozilla::jni::ExceptionMode::ABORT;
-        static const mozilla::jni::CallingThread callingThread =
-                mozilla::jni::CallingThread::GECKO;
-        static const mozilla::jni::DispatchTarget dispatchTarget =
-                mozilla::jni::DispatchTarget::CURRENT;
-    };
-
-    static auto DisableAlarm() -> void;
-
     struct DisableBatteryNotifications_t {
         typedef GeckoAppShell Owner;
         typedef void ReturnType;
         typedef void SetterType;
         typedef mozilla::jni::Args<> Args;
         static constexpr char name[] = "disableBatteryNotifications";
         static constexpr char signature[] =
                 "()V";
@@ -1726,37 +1677,16 @@ public:
         static const mozilla::jni::CallingThread callingThread =
                 mozilla::jni::CallingThread::GECKO;
         static const mozilla::jni::DispatchTarget dispatchTarget =
                 mozilla::jni::DispatchTarget::CURRENT;
     };
 
     static auto ScheduleRestart() -> void;
 
-    struct SetAlarm_t {
-        typedef GeckoAppShell Owner;
-        typedef bool ReturnType;
-        typedef bool SetterType;
-        typedef mozilla::jni::Args<
-                int32_t,
-                int32_t> Args;
-        static constexpr char name[] = "setAlarm";
-        static constexpr char signature[] =
-                "(II)Z";
-        static const bool isStatic = true;
-        static const mozilla::jni::ExceptionMode exceptionMode =
-                mozilla::jni::ExceptionMode::ABORT;
-        static const mozilla::jni::CallingThread callingThread =
-                mozilla::jni::CallingThread::GECKO;
-        static const mozilla::jni::DispatchTarget dispatchTarget =
-                mozilla::jni::DispatchTarget::CURRENT;
-    };
-
-    static auto SetAlarm(int32_t, int32_t) -> bool;
-
     struct SetFullScreen_t {
         typedef GeckoAppShell Owner;
         typedef void ReturnType;
         typedef void SetterType;
         typedef mozilla::jni::Args<
                 bool> Args;
         static constexpr char name[] = "setFullScreen";
         static constexpr char signature[] =