Move CollectionIndexCache.h from core/html/ to core/dom/.

third_party/WebKit/Source/core/dom/CollectionIndexCache.h

 /*
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2014 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 14 matching lines @@
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * 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.
  */
 
 #ifndef CollectionIndexCache_h
 #define CollectionIndexCache_h
 
+#include "platform/heap/Handle.h"
+
 namespace blink {
 
 template <typename Collection, typename NodeType>
 class CollectionIndexCache {
   DISALLOW_NEW();
 
  public:
   CollectionIndexCache();
 
   bool isEmpty(const Collection& collection) {
@@ skipping 161 matching lines @@
     setCachedNodeCount(currentIndex + 1);
     return nullptr;
   }
   setCachedNode(currentNode, currentIndex);
   return currentNode;
 }
 
 }  // namespace blink
 
 #endif  // CollectionIndexCache_h