--- a/dom/base/UseCounters.conf
+++ b/dom/base/UseCounters.conf
@@ -82,16 +82,21 @@ attribute DataTransfer.mozItemCount
 attribute DataTransfer.mozCursor
 method DataTransfer.mozTypesAt
 method DataTransfer.mozClearDataAt
 method DataTransfer.mozSetDataAt
 method DataTransfer.mozGetDataAt
 attribute DataTransfer.mozUserCancelled
 attribute DataTransfer.mozSourceNode
 
+// Marquee events
+custom onstart sets a <marquee> onstart event listener
+custom onbounce sets a <marquee> onbounce event listener
+custom onfinish sets a <marquee> onfinish event listener
+
 // JavaScript feature usage
 custom JS_asmjs uses asm.js
 custom JS_wasm uses WebAssembly
 
 // Console API
 method console.assert
 method console.clear
 method console.count

--- a/dom/events/EventListenerManager.cpp
+++ b/dom/events/EventListenerManager.cpp
@@ -409,16 +409,37 @@ EventListenerManager::AddEventListenerIn
     if (!aFlags.mInSystemGroup) {
       mMayHaveInputOrCompositionEventListener = true;
     }
   } else if (aEventMessage == eSelectionChange) {
     mMayHaveSelectionChangeEventListener = true;
      if (nsPIDOMWindowInner* window = GetInnerWindowForTarget()) {
       window->SetHasSelectionChangeEventListeners();
     }
+  } else if (aTypeAtom == nsGkAtoms::onstart) {
+    if (nsPIDOMWindowInner* window = GetInnerWindowForTarget()) {
+      nsCOMPtr<nsIDocument> doc = window->GetExtantDoc();
+      if (doc) {
+        doc->SetDocumentAndPageUseCounter(eUseCounter_custom_onstart);
+      }
+    }
+  } else if (aTypeAtom == nsGkAtoms::onbounce) {
+    if (nsPIDOMWindowInner* window = GetInnerWindowForTarget()) {
+      nsCOMPtr<nsIDocument> doc = window->GetExtantDoc();
+      if (doc) {
+        doc->SetDocumentAndPageUseCounter(eUseCounter_custom_onbounce);
+      }
+    }
+  } else if (aTypeAtom == nsGkAtoms::onfinish) {
+    if (nsPIDOMWindowInner* window = GetInnerWindowForTarget()) {
+      nsCOMPtr<nsIDocument> doc = window->GetExtantDoc();
+      if (doc) {
+        doc->SetDocumentAndPageUseCounter(eUseCounter_custom_onfinish);
+      }
+    }
   }
 
   if (IsApzAwareListener(listener)) {
     ProcessApzAwareEventListenerAdd();
   }
 
   if (mTarget) {
     if (aTypeAtom) {

--- a/xpcom/ds/nsGkAtomList.h
+++ b/xpcom/ds/nsGkAtomList.h
@@ -687,16 +687,17 @@ GK_ATOM(onauxclick, "onauxclick")
 GK_ATOM(onbeforecopy, "onbeforecopy")
 GK_ATOM(onbeforecut, "onbeforecut")
 GK_ATOM(onbeforepaste, "onbeforepaste")
 GK_ATOM(onbeforeprint, "onbeforeprint")
 GK_ATOM(onbeforescriptexecute, "onbeforescriptexecute")
 GK_ATOM(onbeforeunload, "onbeforeunload")
 GK_ATOM(onblocked, "onblocked")
 GK_ATOM(onblur, "onblur")
+GK_ATOM(onbounce, "onbounce")
 GK_ATOM(onbroadcast, "onbroadcast")
 GK_ATOM(onbufferedamountlow, "onbufferedamountlow")
 GK_ATOM(oncached, "oncached")
 GK_ATOM(oncancel, "oncancel")
 GK_ATOM(onchange, "onchange")
 GK_ATOM(onchargingchange, "onchargingchange")
 GK_ATOM(onchargingtimechange, "onchargingtimechange")
 GK_ATOM(onchecking, "onchecking")