Implement a Hit Test Cache.

Source/core/testing/Internals.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 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.
@@ skipping 299 matching lines @@
 unsigned Internals::hitTestCount(Document* doc, ExceptionState& exceptionState) const
 {
     if (!doc) {
         exceptionState.throwDOMException(InvalidAccessError, "Must supply document to check");
         return 0;
     }
 
     return doc->layoutView()->hitTestCount();
 }
 
+unsigned Internals::hitTestCacheHits(Document* doc, ExceptionState& exceptionState) const
+{
+    if (!doc) {
+        exceptionState.throwDOMException(InvalidAccessError, "Must supply document to check");
+        return 0;
+    }
+
+    return doc->layoutView()->hitTestCacheHits();
+}
+
+Element* Internals::elementFromPointNoCache(Document* doc, double x, double y, ExceptionState& exceptionState) const
+{
+    if (!doc) {
+        exceptionState.throwDOMException(InvalidAccessError, "Must supply document to check");
+        return 0;
+    }
+
+    if (!doc->layoutView())
+        return 0;
+
+    return doc->elementFromPointNoCache(x, y);
+}
+
+void Internals::clearHitTestCache(Document* doc, ExceptionState& exceptionState) const
+{
+    if (!doc) {
+        exceptionState.throwDOMException(InvalidAccessError, "Must supply document to check");
+        return;
+    }
+
+    if (!doc->layoutView())
+        return;
+
+    doc->layoutView()->clearHitTestCache();
+}
 
 bool Internals::isPreloaded(const String& url)
 {
     Document* document = contextDocument();
     return document->fetcher()->isPreloaded(document->completeURL(url));
 }
 
 bool Internals::isLoadingFromMemoryCache(const String& url)
 {
     if (!contextDocument())
@@ skipping 2034 matching lines @@
 
 ClientRectList* Internals::focusRingRects(Element* element)
 {
     Vector<LayoutRect> rects;
     if (element && element->layoutObject())
         element->layoutObject()->addFocusRingRects(rects, LayoutPoint());
     return ClientRectList::create(rects);
 }
 
 } // namespace blink