Add a use counter for creating processing instructions on HTML docs

third_party/WebKit/Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
@@ skipping 979 matching lines @@
         InvalidCharacterError,
         "The target provided ('" + target + "') is not a valid name.");
     return nullptr;
   }
   if (data.contains("?>")) {
     exceptionState.throwDOMException(
         InvalidCharacterError,
         "The data provided ('" + data + "') contains '?>'.");
     return nullptr;
   }
+  if (isHTMLDocument()) {
+    UseCounter::count(*this,
+                      UseCounter::HTMLDocumentCreateProcessingInstruction);
+  }
   return ProcessingInstruction::create(*this, target, data);
 }
 
 Text* Document::createEditingTextNode(const String& text) {
   return Text::createEditingText(*this, text);
 }
 
 bool Document::importContainerNodeChildren(ContainerNode* oldContainerNode,
                                            ContainerNode* newContainerNode,
                                            ExceptionState& exceptionState) {
@@ skipping 5588 matching lines @@
 }
 
 void showLiveDocumentInstances() {
   WeakDocumentSet& set = liveDocumentSet();
   fprintf(stderr, "There are %u documents currently alive:\n", set.size());
   for (blink::Document* document : set)
     fprintf(stderr, "- Document %p URL: %s\n", document,
             document->url().getString().utf8().data());
 }
 #endif