Revert of Remove StringBuilder::appendLiteral.

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

Index: third_party/WebKit/Source/core/css/CSSKeyframesRule.cpp
diff --git a/third_party/WebKit/Source/core/css/CSSKeyframesRule.cpp b/third_party/WebKit/Source/core/css/CSSKeyframesRule.cpp
index f81050542d1123d4c880a229b882de7fa81bba98..3c1c50d2dce2604a86f2c573432cf89505238c7c 100644
--- a/third_party/WebKit/Source/core/css/CSSKeyframesRule.cpp
+++ b/third_party/WebKit/Source/core/css/CSSKeyframesRule.cpp
@@ -153,15 +153,15 @@
 {
     StringBuilder result;
     if (isVendorPrefixed())
-        result.append("@-webkit-keyframes ");
+        result.appendLiteral("@-webkit-keyframes ");
     else
-        result.append("@keyframes ");
+        result.appendLiteral("@keyframes ");
     result.append(name());
-    result.append(" { \n");
+    result.appendLiteral(" { \n");
 
     unsigned size = length();
     for (unsigned i = 0; i < size; ++i) {
-        result.append("  ");
+        result.appendLiteral("  ");
         result.append(m_keyframesRule->keyframes()[i]->cssText());
         result.append('\n');
     }