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

Source/core/css/CSSCalculationValue.cpp

 /*
  * Copyright (C) 2011, 2012 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 128 matching lines @@
     case CSSPrimitiveValue::CSS_VALUE_ID:
         return false;
     };
     ASSERT_NOT_REACHED();
     return false;
 }
 
 static String buildCSSText(const String& expression)
 {
     StringBuilder result;
-    result.append("calc");
+    result.appendLiteral("calc");
     bool expressionHasSingleTerm = expression[0] != '(';
     if (expressionHasSingleTerm)
         result.append('(');
     result.append(expression);
     if (expressionHasSingleTerm)
         result.append(')');
     return result.toString();
 }
 
 String CSSCalcValue::customCSSText() const
@@ skipping 605 matching lines @@
     return adoptRefWillBeNoop(new CSSCalcValue(expression, range));
 }
 
 void CSSCalcValue::traceAfterDispatch(Visitor* visitor)
 {
     visitor->trace(m_expression);
     CSSValue::traceAfterDispatch(visitor);
 }
 
 } // namespace blink