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

Source/core/rendering/GraphicsContextAnnotator.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  * Copyright (C) 2013 Samsung Electronics. 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.
@@ skipping 94 matching lines @@
 
     if ((mode & AnnotateElementId) && element && element->hasID())
         annotations.append(std::make_pair(AnnotationKeyElementId, element->getIdAttribute().string()));
 
     if ((mode & AnnotateElementClass) && element && element->hasClass()) {
         SpaceSplitString classes = element->classNames();
         if (!classes.isNull() && classes.size() > 0) {
             StringBuilder classBuilder;
             for (size_t i = 0; i < classes.size(); ++i) {
                 if (i > 0)
-                    classBuilder.append(" ");
+                    classBuilder.append(' ');
                 classBuilder.append(classes[i]);
             }
 
             annotations.append(std::make_pair(AnnotationKeyElementClass, classBuilder.toString()));
         }
     }
 
     if ((mode & AnnotateElementTag) && element)
         annotations.append(std::make_pair(AnnotationKeyElementTag, element->tagName()));
 
     if (mode & AnnotateInspectorId) {
         if (Node* ownerNode = object->generatingNode()) {
             annotations.append(std::make_pair(AnnotationKeyInspectorNodeId,
                 String::number(InspectorNodeIds::idForNode(ownerNode))));
         }
     }
 
     m_context = paintInfo.context;
     m_context->beginAnnotation(annotations);
 }
 
 void GraphicsContextAnnotator::finishAnnotation()
 {
     ASSERT(m_context);
     m_context->endAnnotation();
 }
 
 } // namespace blink