Bug 1894380 - Fix the nsUrlClassifierPrefixSet destructor. r=dimi

Differential Revision: https://phabricator.services.mozilla.com/D210625

toolkit/components/url-classifier/nsUrlClassifierPrefixSet.cpp

@@ -37,6 +37,8 @@ nsUrlClassifierPrefixSet::Init(const nsACString& aName) {
 }
 
 nsUrlClassifierPrefixSet::~nsUrlClassifierPrefixSet() {
+  MutexAutoLock lock(mLock);
+
   for (uint32_t i = 0; i < mIndexDeltas.Length(); i++) {
     mIndexDeltas[i].Clear();
   }

toolkit/components/url-classifier/nsUrlClassifierPrefixSet.h

@@ -51,7 +51,7 @@ class nsUrlClassifierPrefixSet final : public nsIUrlClassifierPrefixSet {
   friend class mozilla::safebrowsing::VariableLengthPrefixSet;
 
  private:
-  virtual ~nsUrlClassifierPrefixSet();
+  virtual ~nsUrlClassifierPrefixSet() MOZ_REQUIRES(mLock);
 
   static const uint32_t DELTAS_LIMIT = 120;
   static const uint32_t MAX_INDEX_DIFF = (1 << 16);