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

third_party/WebKit/Source/core/css/parser/CSSParserImpl.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/css/parser/CSSParserImpl.h"
 
 #include "core/css/CSSCustomIdentValue.h"
 #include "core/css/CSSCustomPropertyDeclaration.h"
 #include "core/css/CSSKeyframesRule.h"
 #include "core/css/CSSStyleSheet.h"
@@ skipping 102 matching lines @@
     const CSSProperty& property = input[i];
     if (property.isImportant() != important)
       continue;
     const unsigned propertyIDIndex = property.id() - firstCSSProperty;
 
     if (property.id() == CSSPropertyVariable) {
       const AtomicString& name =
           toCSSCustomPropertyDeclaration(property.value())->name();
       if (seenCustomProperties.contains(name))
         continue;
-      seenCustomProperties.add(name);
+      seenCustomProperties.insert(name);
     } else if (property.id() == CSSPropertyApplyAtRule) {
       // TODO(timloh): Do we need to do anything here?
     } else {
       if (seenProperties.test(propertyIDIndex))
         continue;
       seenProperties.set(propertyIDIndex);
     }
     output[--unusedEntries] = property;
   }
 }
@@ skipping 845 matching lines @@
     else
       return nullptr;  // Parser error, invalid value in keyframe selector
     if (range.atEnd())
       return result;
     if (range.consume().type() != CommaToken)
       return nullptr;  // Parser error
   }
 }
 
 }  // namespace blink