Introduce use counters for Blink specific CSS classes for editing

Source/core/editing/ApplyStyleCommand.cpp

 /*
  * Copyright (C) 2005, 2006, 2008, 2009 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 25 matching lines @@
 #include "core/dom/NodeList.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/dom/Range.h"
 #include "core/dom/Text.h"
 #include "core/editing/EditingStyle.h"
 #include "core/editing/HTMLInterchange.h"
 #include "core/editing/PlainTextRange.h"
 #include "core/editing/TextIterator.h"
 #include "core/editing/VisibleUnits.h"
 #include "core/editing/htmlediting.h"
+#include "core/frame/UseCounter.h"
 #include "core/rendering/RenderObject.h"
 #include "core/rendering/RenderText.h"
 #include "platform/heap/Handle.h"
 #include "wtf/StdLibExtras.h"
 #include "wtf/text/StringBuilder.h"
 
 namespace WebCore {
 
 using namespace HTMLNames;
 
 static String& styleSpanClassString()
 {
     DEFINE_STATIC_LOCAL(String, styleSpanClassString, ((AppleStyleSpanClass)));
     return styleSpanClassString;
 }
 
 bool isLegacyAppleStyleSpan(const Node *node)
 {
     if (!node || !node->isHTMLElement())
         return false;
 
     const HTMLElement* elem = toHTMLElement(node);
-    return elem->hasLocalName(spanAttr) && elem->getAttribute(classAttr) == styleSpanClassString();
+    if (!elem->hasLocalName(spanAttr) || elem->getAttribute(classAttr) != styleSpanClassString())
+        return false;
+    UseCounter::count(elem->document(), UseCounter::EditingAppleStyleSpanClass);
+    return true;
 }
 
 static bool hasNoAttributeOrOnlyStyleAttribute(const Element* element, ShouldStyleAttributeBeEmpty shouldStyleAttributeBeEmpty)
 {
     if (!element->hasAttributes())
         return true;
 
     unsigned matchedAttributes = 0;
     if (element->getAttribute(classAttr) == styleSpanClassString())
         matchedAttributes++;
@@ skipping 1488 matching lines @@
 void ApplyStyleCommand::trace(Visitor* visitor)
 {
     visitor->trace(m_style);
     visitor->trace(m_start);
     visitor->trace(m_end);
     visitor->trace(m_styledInlineElement);
     CompositeEditCommand::trace(visitor);
 }
 
 }