Migrate WTF::HashSet::add() to ::insert() [part 1 of N]

third_party/WebKit/Source/core/inspector/DOMPatchSupport.cpp

Index: third_party/WebKit/Source/core/inspector/DOMPatchSupport.cpp
diff --git a/third_party/WebKit/Source/core/inspector/DOMPatchSupport.cpp b/third_party/WebKit/Source/core/inspector/DOMPatchSupport.cpp
index d60da0bd5c2fb1466f8c84e0e1dcab808a29c65b..996f1833b65d4112b6d66ed5eafa3ea50fc94e1b 100644
--- a/third_party/WebKit/Source/core/inspector/DOMPatchSupport.cpp
+++ b/third_party/WebKit/Source/core/inspector/DOMPatchSupport.cpp
@@ -335,7 +335,7 @@ bool DOMPatchSupport::innerPatchChildren(
       usedNewOrdinals;
   for (size_t i = 0; i < oldList.size(); ++i) {
     if (oldMap[i].first) {
-      if (usedNewOrdinals.add(oldMap[i].second).isNewEntry)
+      if (usedNewOrdinals.insert(oldMap[i].second).isNewEntry)
         continue;
       oldMap[i].first = 0;
       oldMap[i].second = 0;
@@ -387,7 +387,7 @@ bool DOMPatchSupport::innerPatchChildren(
       newMap[i].second = 0;
       continue;
     }
-    usedOldOrdinals.add(oldOrdinal);
+    usedOldOrdinals.insert(oldOrdinal);
     markNodeAsUsed(newMap[i].first);
   }