Add test to track the number of hit tests on various events

Source/core/testing/Internals.cpp

Index: Source/core/testing/Internals.cpp
diff --git a/Source/core/testing/Internals.cpp b/Source/core/testing/Internals.cpp
index 05fd3f92a0893982f5b9a9bf378e926d135aca1c..8ac6035cd745a735079c9459a97ae454b111feb7 100644
--- a/Source/core/testing/Internals.cpp
+++ b/Source/core/testing/Internals.cpp
@@ -296,6 +296,17 @@ unsigned Internals::needsLayoutCount(ExceptionState& exceptionState) const
     return needsLayoutObjects;
 }
 
+unsigned Internals::hitTestCount(Document* doc, ExceptionState& exceptionState) const
+{
+    if (!doc) {
+        exceptionState.throwDOMException(InvalidAccessError, "Must supply document to check");
+        return 0;
+    }
+
+    return doc->renderView()->hitTestCount();
+}
+
+
 bool Internals::isPreloaded(const String& url)
 {
     Document* document = contextDocument();