Bug 1661462 - Add a pref to control min timeout delays in background windows before throttling has started, r=farre

Differential Revision: https://phabricator.services.mozilla.com/D88414

dom/base/TimeoutManager.cpp

@@ -249,7 +249,11 @@ TimeDuration TimeoutManager::MinSchedulingDelay() const {
     double factor = 1.0 / GetRegenerationFactor(mWindow.IsBackgroundInternal());
     return TimeDuration::Max(unthrottled, -mExecutionBudget.MultDouble(factor));
   }
-  //
+  if (!mThrottleTimeouts && isBackground) {
+    return TimeDuration::FromMilliseconds(
+        StaticPrefs::dom_min_background_timeout_value_before_throttling());
+  }
+
   return unthrottled;
 }
 

modules/libpref/init/StaticPrefList.yaml

@@ -2159,6 +2159,12 @@
   value: 1000
   mirror: always
 
+# Timeout clamp in ms for background windows before throttling has started.
+- name: dom.min_background_timeout_value_before_throttling
+  type: int32_t
+  value: 1000
+  mirror: always
+
 # Are missing-property use counters for certain DOM attributes enabled?
 - name: dom.missing_prop_counters.enabled
   type: bool