Bug 1656114 - Part 3: Switch use counter storage to mozilla::BitSet. r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D87187

dom/base/Document.cpp

@@ -1363,8 +1363,6 @@ Document::Document(const char* aContentType)
       mBFCacheEntry(nullptr),
       mInSyncOperationCount(0),
       mBlockDOMContentLoaded(0),
-      mUseCounters(0),
-      mChildDocumentUseCounters(0),
       mUserHasInteracted(false),
       mHasUserInteractionTimerScheduled(false),
       mStackRefCnt(0),

dom/base/Document.h

@@ -4839,9 +4839,9 @@ class Document : public nsINode,
   nsTObserverArray<nsIDocumentObserver*> mObservers;
 
   // Flags for use counters used directly by this document.
-  std::bitset<eUseCounter_Count> mUseCounters;
+  UseCounters mUseCounters;
   // Flags for use counters used by any child documents of this document.
-  std::bitset<eUseCounter_Count> mChildDocumentUseCounters;
+  UseCounters mChildDocumentUseCounters;
 
   // The CSS property use counters.
   UniquePtr<StyleUseCounters> mStyleUseCounters;

dom/base/UseCounter.h

@@ -7,6 +7,7 @@
 #define UseCounter_h_
 
 #include <stdint.h>
+#include "mozilla/BitSet.h"
 
 namespace mozilla {
 
@@ -59,6 +60,8 @@ enum UseCounter : int16_t {
   eUseCounter_Count
 };
 
+using UseCounters = BitSet<eUseCounter_Count, uint64_t>;
+
 enum class UseCounterWorker : int16_t {
   Unknown = -1,
 #define USE_COUNTER_DOM_METHOD(interface_, name_) interface_##_##name_,