Add use counters for elements used in Shadow DOM

third_party/WebKit/Source/core/html/HTMLShadowElement.cpp

 /*
  * Copyright (C) 2012 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 15 matching lines @@
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "core/html/HTMLShadowElement.h"
 
 #include "core/HTMLNames.h"
 #include "core/dom/Document.h"
 #include "core/dom/shadow/ShadowRoot.h"
+#include "core/frame/UseCounter.h"
 #include "core/inspector/ConsoleMessage.h"
 
 namespace blink {
 
 class Document;
 
 inline HTMLShadowElement::HTMLShadowElement(Document& document)
-    : InsertionPoint(HTMLNames::shadowTag, document) {}
+    : InsertionPoint(HTMLNames::shadowTag, document) {
+  UseCounter::count(document, UseCounter::HTMLShadowElement);
+}
 
 DEFINE_NODE_FACTORY(HTMLShadowElement)
 
 HTMLShadowElement::~HTMLShadowElement() {}
 
 ShadowRoot* HTMLShadowElement::olderShadowRoot() {
   ShadowRoot* containingRoot = containingShadowRoot();
   if (!containingRoot)
     return nullptr;
 
@@ skipping 19 matching lines @@
           String::format("<shadow> doesn't work for %s element host.",
                          root->host().tagName().utf8().data());
       document().addConsoleMessage(ConsoleMessage::create(
           RenderingMessageSource, WarningMessageLevel, message));
     }
   }
   return InsertionPoint::insertedInto(insertionPoint);
 }
 
 }  // namespace blink