Use StringBuilder::appendLiteral() / StringBuilder::append(char) when possible

Source/core/dom/DatasetDOMStringMap.cpp

 /*
  * Copyright (C) 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 107 matching lines @@
             return false;
     }
     return true;
 }
 
 // This returns an AtomicString because attribute names are always stored
 // as AtomicString types in Element (see setAttribute()).
 static AtomicString convertPropertyNameToAttributeName(const String& name)
 {
     StringBuilder builder;
-    builder.append("data-");
+    builder.appendLiteral("data-");
 
     unsigned length = name.length();
     for (unsigned i = 0; i < length; ++i) {
         UChar character = name[i];
         if (isASCIIUpper(character)) {
             builder.append('-');
             builder.append(toASCIILower(character));
         } else
             builder.append(character);
     }
@@ skipping 68 matching lines @@
     return false;
 }
 
 void DatasetDOMStringMap::trace(Visitor* visitor)
 {
     visitor->trace(m_element);
     DOMStringMap::trace(visitor);
 }
 
 } // namespace blink