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

Source/core/css/CSSFilterValue.cpp

 /*
  * Copyright (C) 2011 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 23 matching lines @@
     : CSSValueList(CSSFilterClass, CommaSeparator)
     , m_type(operationType)
 {
 }
 
 String CSSFilterValue::customCSSText() const
 {
     StringBuilder result;
     switch (m_type) {
     case ReferenceFilterOperation:
-        result.append("url(");
+        result.appendLiteral("url(");
         break;
     case GrayscaleFilterOperation:
-        result.append("grayscale(");
+        result.appendLiteral("grayscale(");
         break;
     case SepiaFilterOperation:
-        result.append("sepia(");
+        result.appendLiteral("sepia(");
         break;
     case SaturateFilterOperation:
-        result.append("saturate(");
+        result.appendLiteral("saturate(");
         break;
     case HueRotateFilterOperation:
-        result.append("hue-rotate(");
+        result.appendLiteral("hue-rotate(");
         break;
     case InvertFilterOperation:
-        result.append("invert(");
+        result.appendLiteral("invert(");
         break;
     case OpacityFilterOperation:
-        result.append("opacity(");
+        result.appendLiteral("opacity(");
         break;
     case BrightnessFilterOperation:
-        result.append("brightness(");
+        result.appendLiteral("brightness(");
         break;
     case ContrastFilterOperation:
-        result.append("contrast(");
+        result.appendLiteral("contrast(");
         break;
     case BlurFilterOperation:
-        result.append("blur(");
+        result.appendLiteral("blur(");
         break;
     case DropShadowFilterOperation:
-        result.append("drop-shadow(");
+        result.appendLiteral("drop-shadow(");
         break;
     default:
         break;
     }
 
     result.append(CSSValueList::customCSSText());
     result.append(')');
     return result.toString();
 }
 
 CSSFilterValue::CSSFilterValue(const CSSFilterValue& cloneFrom)
     : CSSValueList(cloneFrom)
     , m_type(cloneFrom.m_type)
 {
 }
 
 PassRefPtrWillBeRawPtr<CSSFilterValue> CSSFilterValue::cloneForCSSOM() const
 {
     return adoptRefWillBeNoop(new CSSFilterValue(*this));
 }
 
 bool CSSFilterValue::equals(const CSSFilterValue& other) const
 {
     return m_type == other.m_type && CSSValueList::equals(other);
 }
 
 }