Migrate WTF::HashMap::add() to ::insert()

third_party/WebKit/Source/core/css/RuleFeature.cpp

Index: third_party/WebKit/Source/core/css/RuleFeature.cpp
diff --git a/third_party/WebKit/Source/core/css/RuleFeature.cpp b/third_party/WebKit/Source/core/css/RuleFeature.cpp
index ae095962c7f317c5a2bbe8aeb5ed629168eac565..31227852af3a4d175212a7e44d971750f30ffc63 100644
--- a/third_party/WebKit/Source/core/css/RuleFeature.cpp
+++ b/third_party/WebKit/Source/core/css/RuleFeature.cpp
@@ -229,7 +229,7 @@ InvalidationSet& ensureInvalidationSet(
     const AtomicString& key,
     InvalidationType type) {
   RefPtr<InvalidationSet>& invalidationSet =
-      map.add(key, nullptr).storedValue->value;
+      map.insert(key, nullptr).storedValue->value;
   return storedInvalidationSet(invalidationSet, type);
 }
 
@@ -241,7 +241,7 @@ InvalidationSet& ensureInvalidationSet(
     CSSSelector::PseudoType key,
     InvalidationType type) {
   RefPtr<InvalidationSet>& invalidationSet =
-      map.add(key, nullptr).storedValue->value;
+      map.insert(key, nullptr).storedValue->value;
   return storedInvalidationSet(invalidationSet, type);
 }