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

Source/platform/PODInterval.h

 /*
  * Copyright (C) 2010 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:
  *
  * 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
@@ skipping 120 matching lines @@
     }
 
     const T& maxHigh() const { return m_maxHigh; }
     void setMaxHigh(const T& maxHigh) { m_maxHigh = maxHigh; }
 
 #ifndef NDEBUG
     // Support for printing PODIntervals.
     String toString() const
     {
         StringBuilder builder;
-        builder.append("[PODInterval (");
+        builder.appendLiteral("[PODInterval (");
         builder.append(ValueToString<T>::string(low()));
-        builder.append(", ");
+        builder.appendLiteral(", ");
         builder.append(ValueToString<T>::string(high()));
-        builder.append("), data=");
+        builder.appendLiteral("), data=");
         builder.append(ValueToString<UserData>::string(data()));
-        builder.append(", maxHigh=");
+        builder.appendLiteral(", maxHigh=");
         builder.append(ValueToString<T>::string(maxHigh()));
-        builder.append("]");
+        builder.append(']');
         return builder.toString();
     }
 #endif
 
 private:
     T m_low;
     T m_high;
     UserData m_data;
     T m_maxHigh;
 };
 
 } // namespace blink
 
 #endif // PODInterval_h