Revert of Remove StringBuilder::appendLiteral.

third_party/WebKit/Source/core/css/CSSFontFaceSrcValue.cpp

Index: third_party/WebKit/Source/core/css/CSSFontFaceSrcValue.cpp
diff --git a/third_party/WebKit/Source/core/css/CSSFontFaceSrcValue.cpp b/third_party/WebKit/Source/core/css/CSSFontFaceSrcValue.cpp
index 42504fcd08b39e6a07b722653a7b7abebe80fba7..99d39f6f751fa09ea110ce465b65b818f13bdbdd 100644
--- a/third_party/WebKit/Source/core/css/CSSFontFaceSrcValue.cpp
+++ b/third_party/WebKit/Source/core/css/CSSFontFaceSrcValue.cpp
@@ -56,16 +56,16 @@
 {
     StringBuilder result;
     if (isLocal()) {
-        result.append("local(");
+        result.appendLiteral("local(");
         result.append(serializeString(m_absoluteResource));
-        result.append(")");
+        result.appendLiteral(")");
     } else {
         result.append(serializeURI(m_specifiedResource));
     }
     if (!m_format.isEmpty()) {
-        result.append(" format(");
+        result.appendLiteral(" format(");
         result.append(serializeString(m_format));
-        result.append(")");
+        result.appendLiteral(")");
     }
     return result.toString();
 }