Mark DOMStringList.contains() as deprecated, add console warning.

Source/core/dom/DOMStringList.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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 18 matching lines @@
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "core/CoreExport.h"
 #include "platform/heap/Handle.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 #include "wtf/Vector.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
+class ExecutionContext;
+
 // FIXME: Some consumers of this class may benefit from lazily fetching items rather
 //        than creating the list statically as is currently the only option.
 class CORE_EXPORT DOMStringList final : public RefCountedWillBeGarbageCollectedFinalized<DOMStringList>, public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
-    static PassRefPtrWillBeRawPtr<DOMStringList> create()
+    // We would like to remove DOMStringList from the platform if possible.
+    // Track the source of each instance so we can measure the use of methods
+    // not present on Arrays and determine the feasibility of removal and
+    // what path it should take. http://crbug.com/460726
+    enum Source { IndexedDB, Location };
+
+    static PassRefPtrWillBeRawPtr<DOMStringList> create(Source source)
     {
-        return adoptRefWillBeNoop(new DOMStringList());
+        return adoptRefWillBeNoop(new DOMStringList(source));
     }
 
     bool isEmpty() const { return m_strings.isEmpty(); }
     void clear() { m_strings.clear(); }
     void append(const String& string) { m_strings.append(string); }
     void sort();
 
     // Implements the IDL.
     size_t length() const { return m_strings.size(); }
-    String item(unsigned index) const;
-    bool contains(const String& str) const;
+    String anonymousIndexedGetter(unsigned index) const;
+
+    String item(ExecutionContext*, unsigned index) const;
+    bool contains(ExecutionContext*, const String&) const;
 
     operator const Vector<String>&() const { return m_strings; }
 
     DEFINE_INLINE_TRACE() { }
 
 private:
-    DOMStringList() { }
+    DOMStringList(Source source) : m_source(source) { }
 
     Vector<String> m_strings;
+    Source m_source;
 };
 
 } // namespace blink
 
 #endif // DOMStringList_h