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

Source/core/rendering/RenderView.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 42 matching lines @@
     , m_frameView(document->view())
     , m_selectionStart(0)
     , m_selectionEnd(0)
     , m_selectionStartPos(-1)
     , m_selectionEndPos(-1)
     , m_pageLogicalHeight(0)
     , m_pageLogicalHeightChanged(false)
     , m_layoutState(0)
     , m_renderQuoteHead(0)
     , m_renderCounterCount(0)
+    , m_hitTestCount(0)
 {
     // init RenderObject attributes
     setInline(false);
 
     m_minPreferredLogicalWidth = 0;
     m_maxPreferredLogicalWidth = 0;
 
     setPreferredLogicalWidthsDirty(MarkOnlyThis);
 
     setPositionState(AbsolutePosition); // to 0,0 :)
 }
 
 RenderView::~RenderView()
 {
 }
 
 bool RenderView::hitTest(const HitTestRequest& request, HitTestResult& result)
 {
     return hitTest(request, result.hitTestLocation(), result);
 }
 
 bool RenderView::hitTest(const HitTestRequest& request, const HitTestLocation& location, HitTestResult& result)
 {
     TRACE_EVENT0("blink", "RenderView::hitTest");
+    m_hitTestCount++;
 
     // We have to recursively update layout/style here because otherwise, when the hit test recurses
     // into a child document, it could trigger a layout on the parent document, which can destroy RenderLayers
     // that are higher up in the call stack, leading to crashes.
     // Note that Document::updateLayout calls its parent's updateLayout.
     // FIXME: It should be the caller's responsibility to ensure an up-to-date layout.
     frameView()->updateLayoutAndStyleIfNeededRecursive();
     return layer()->hitTest(request, location, result);
 }
 
@@ skipping 895 matching lines @@
     return viewWidth(IncludeScrollbars) / scale;
 }
 
 double RenderView::layoutViewportHeight() const
 {
     float scale = m_frameView ? m_frameView->frame().pageZoomFactor() : 1;
     return viewHeight(IncludeScrollbars) / scale;
 }
 
 } // namespace WebCore