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

third_party/WebKit/Source/core/dom/ChildListMutationScope.cpp

Index: third_party/WebKit/Source/core/dom/ChildListMutationScope.cpp
diff --git a/third_party/WebKit/Source/core/dom/ChildListMutationScope.cpp b/third_party/WebKit/Source/core/dom/ChildListMutationScope.cpp
index f6742602861d37388701ce809419196b6fa3bcbc..b96ccf192da2146b2bff3748579c73a863f2c439 100644
--- a/third_party/WebKit/Source/core/dom/ChildListMutationScope.cpp
+++ b/third_party/WebKit/Source/core/dom/ChildListMutationScope.cpp
@@ -69,7 +69,7 @@ void ChildListMutationAccumulator::leaveMutationScope() {
 
 ChildListMutationAccumulator* ChildListMutationAccumulator::getOrCreate(
     Node& target) {
-  AccumulatorMap::AddResult result = accumulatorMap().add(&target, nullptr);
+  AccumulatorMap::AddResult result = accumulatorMap().insert(&target, nullptr);
   ChildListMutationAccumulator* accumulator;
   if (!result.isNewEntry) {
     accumulator = result.storedValue->value;