--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -4160,64 +4160,29 @@ HTMLMediaElement::WakeLockBoolWrapper::o
     return *this;
   }
 
   mValue = val;
   UpdateWakeLock();
   return *this;
 }
 
-HTMLMediaElement::WakeLockBoolWrapper::~WakeLockBoolWrapper()
-{
-  if (mTimer) {
-    mTimer->Cancel();
-  }
-}
-
 void
 HTMLMediaElement::WakeLockBoolWrapper::UpdateWakeLock()
 {
   MOZ_ASSERT(NS_IsMainThread());
-
-  if (!mOuter) {
-    return;
-  }
+  MOZ_ASSERT(mOuter);
 
   bool playing = !mValue;
 
   if (playing) {
-    if (mTimer) {
-      mTimer->Cancel();
-      mTimer = nullptr;
-    }
     mOuter->WakeLockCreate();
-  } else if (!mTimer) {
-    // Don't release the wake lock immediately; instead, release it after a
-    // grace period.
-    int timeout = Preferences::GetInt("media.wakelock_timeout", 2000);
-    mTimer = do_CreateInstance("@mozilla.org/timer;1");
-    if (mTimer) {
-      mTimer->SetTarget(mOuter->MainThreadEventTarget());
-      mTimer->InitWithNamedFuncCallback(
-        TimerCallback,
-        this,
-        timeout,
-        nsITimer::TYPE_ONE_SHOT,
-        "dom::HTMLMediaElement::WakeLockBoolWrapper::UpdateWakeLock");
-    }
-  }
-}
-
-void
-HTMLMediaElement::WakeLockBoolWrapper::TimerCallback(nsITimer* aTimer,
-                                                     void* aClosure)
-{
-  WakeLockBoolWrapper* wakeLock = static_cast<WakeLockBoolWrapper*>(aClosure);
-  wakeLock->mOuter->WakeLockRelease();
-  wakeLock->mTimer = nullptr;
+  } else {
+    mOuter->WakeLockRelease();
+  }
 }
 
 void
 HTMLMediaElement::WakeLockCreate()
 {
   if (!mWakeLock) {
     RefPtr<power::PowerManagerService> pmService =
       power::PowerManagerService::GetInstance();

--- a/dom/html/HTMLMediaElement.h
+++ b/dom/html/HTMLMediaElement.h
@@ -816,34 +816,31 @@ protected:
 
   class WakeLockBoolWrapper {
   public:
     explicit WakeLockBoolWrapper(bool val = false)
       : mValue(val)
       , mOuter(nullptr)
     {}
 
-    ~WakeLockBoolWrapper();
+    ~WakeLockBoolWrapper() {};
 
     void SetOuter(HTMLMediaElement* outer) { mOuter = outer; }
 
     MOZ_IMPLICIT operator bool() const { return mValue; }
 
     WakeLockBoolWrapper& operator=(bool val);
 
     bool operator !() const { return !mValue; }
 
-    static void TimerCallback(nsITimer* aTimer, void* aClosure);
-
   private:
     void UpdateWakeLock();
 
     bool mValue;
     HTMLMediaElement* mOuter;
-    nsCOMPtr<nsITimer> mTimer;
   };
 
   // Holds references to the DOM wrappers for the MediaStreams that we're
   // writing to.
   struct OutputMediaStream {
     OutputMediaStream();
     ~OutputMediaStream();
 

--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -344,19 +344,16 @@ pref("media.throttle-factor", 2);
 // readahead_limit if the download is fast. This pref toggles the "and the
 // download is fast" check off, so that we can always throttle the download
 // once the readaheadd limit is reached even on a slow network.
 pref("media.throttle-regardless-of-download-rate", false);
 
 // Master HTML5 media volume scale.
 pref("media.volume_scale", "1.0");
 
-// Timeout for wakelock release
-pref("media.wakelock_timeout", 2000);
-
 // Whether we should play videos opened in a "video document", i.e. videos
 // opened as top-level documents, as opposed to inside a media element.
 pref("media.play-stand-alone", true);
 
 pref("media.hardware-video-decoding.enabled", true);
 pref("media.hardware-video-decoding.force-enabled", false);
 
 #ifdef MOZ_FMP4