--- a/dom/base/TimeoutManager.cpp
+++ b/dom/base/TimeoutManager.cpp
@@ -29,19 +29,16 @@
 
 using namespace mozilla;
 using namespace mozilla::dom;
 
 LazyLogModule gTimeoutLog("Timeout");
 
 static int32_t gRunningTimeoutDepth = 0;
 
-#define DEFAULT_ENABLE_BUDGET_TIMEOUT_THROTTLING false
-static bool gEnableBudgetTimeoutThrottling = false;
-
 // static
 const uint32_t TimeoutManager::InvalidFiringId = 0;
 
 namespace {
 double GetRegenerationFactor(bool aIsBackground) {
   // Lookup function for "dom.timeout.{background,
   // foreground}_budget_regeneration_rate".
 
@@ -442,23 +439,16 @@ TimeoutManager::~TimeoutManager() {
 
   mExecutor->Shutdown();
   mIdleExecutor->Shutdown();
 
   MOZ_LOG(gTimeoutLog, LogLevel::Debug,
           ("TimeoutManager %p destroyed\n", this));
 }
 
-/* static */
-void TimeoutManager::Initialize() {
-  Preferences::AddBoolVarCache(&gEnableBudgetTimeoutThrottling,
-                               "dom.timeout.enable_budget_timer_throttling",
-                               DEFAULT_ENABLE_BUDGET_TIMEOUT_THROTTLING);
-}
-
 uint32_t TimeoutManager::GetTimeoutId(Timeout::Reason aReason) {
   switch (aReason) {
     case Timeout::Reason::eIdleCallbackTimeout:
       return ++mIdleCallbackTimeoutCounter;
     case Timeout::Reason::eTimeoutOrInterval:
     default:
       return ++mTimeoutIdCounter;
   }
@@ -1302,17 +1292,18 @@ void TimeoutManager::StartThrottlingTime
   MOZ_DIAGNOSTIC_ASSERT(mThrottleTimeoutsTimer);
 
   MOZ_LOG(gTimeoutLog, LogLevel::Debug,
           ("TimeoutManager %p started to throttle tracking timeouts\n", this));
 
   MOZ_DIAGNOSTIC_ASSERT(!mThrottleTimeouts);
   mThrottleTimeouts = true;
   mThrottleTrackingTimeouts = true;
-  mBudgetThrottleTimeouts = gEnableBudgetTimeoutThrottling;
+  mBudgetThrottleTimeouts =
+      StaticPrefs::dom_timeout_enable_budget_timer_throttling();
   mThrottleTimeoutsTimer = nullptr;
 }
 
 void TimeoutManager::OnDocumentLoaded() {
   // The load event may be firing again if we're coming back to the page by
   // navigating through the session history, so we need to ensure to only call
   // this when mThrottleTimeouts hasn't been set yet.
   if (!mThrottleTimeouts) {

--- a/dom/base/TimeoutManager.h
+++ b/dom/base/TimeoutManager.h
@@ -75,19 +75,16 @@ class TimeoutManager final {
   void Resume();
   void Freeze();
   void Thaw();
 
   // This should be called by nsGlobalWindow when the window might have moved
   // to the background or foreground.
   void UpdateBackgroundState();
 
-  // Initialize TimeoutManager before the first time it is accessed.
-  static void Initialize();
-
   // The document finished loading
   void OnDocumentLoaded();
   void StartThrottlingTimeouts();
 
   // Run some code for each Timeout in our list.  Note that this function
   // doesn't guarantee that Timeouts are iterated in any particular order.
   template <class Callable>
   void ForEachUnorderedTimeout(Callable c) {

--- a/dom/base/nsGlobalWindowInner.cpp
+++ b/dom/base/nsGlobalWindowInner.cpp
@@ -902,26 +902,16 @@ nsGlobalWindowInner::nsGlobalWindowInner
 
   if (XRE_IsContentProcess()) {
     nsCOMPtr<nsIDocShell> docShell = GetDocShell();
     if (docShell) {
       mBrowserChild = docShell->GetBrowserChild();
     }
   }
 
-  // We could have failed the first time through trying
-  // to create the entropy collector, so we should
-  // try to get one until we succeed.
-
-  static bool sFirstTime = true;
-  if (sFirstTime) {
-    sFirstTime = false;
-    TimeoutManager::Initialize();
-  }
-
   if (gDumpFile == nullptr) {
     nsAutoCString fname;
     Preferences::GetCString("browser.dom.window.dump.file", fname);
     if (!fname.IsEmpty()) {
       // If this fails to open, Dump() knows to just go to stdout on null.
       gDumpFile = fopen(fname.get(), "wb+");
     } else {
       gDumpFile = stdout;

--- a/modules/libpref/init/StaticPrefList.yaml
+++ b/modules/libpref/init/StaticPrefList.yaml
@@ -1846,16 +1846,22 @@
   mirror: always
 
 # The maximum amount a timeout can be delayed by budget throttling.
 - name: dom.timeout.budget_throttling_max_delay
   type: int32_t
   value: 15000
   mirror: always
 
+# Turn on budget throttling by default.
+- name: dom.timeout.enable_budget_timer_throttling
+  type: bool
+  value: true
+  mirror: always
+
 # Should we defer timeouts and intervals while loading a page.  Released
 # on Idle or when the page is loaded.
 - name: dom.timeout.defer_during_load
   type: bool
   value: true
   mirror: always
 
 # Maximum amount of time in milliseconds consecutive setTimeout()/setInterval()

--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -1078,19 +1078,16 @@ pref("dom.storage.default_quota",      5
 pref("dom.storage.shadow_writes", true);
 pref("dom.storage.snapshot_prefill", 16384);
 pref("dom.storage.snapshot_gradual_prefill", 4096);
 pref("dom.storage.snapshot_reusing", true);
 pref("dom.storage.client_validation", true);
 
 pref("dom.send_after_paint_to_content", false);
 
-// Turn on budget throttling by default
-pref("dom.timeout.enable_budget_timer_throttling", true);
-
 // Don't use new input types
 pref("dom.experimental_forms", false);
 
 // Enable <input type=color> by default. It will be turned off for remaining
 // platforms which don't have a color picker implemented yet.
 pref("dom.forms.color", true);
 
 // Support for input type=month, type=week and type=datetime-local. By default,