Add hittest mode for Touch-action which ignore inline elements and svg elements

Source/core/rendering/RenderBlock.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 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.
@@ skipping 97 matching lines @@
     static void removePositionedObject(RenderBox*);
     void removePositionedObjects(RenderBlock*, ContainingBlockState = SameContainingBlock);
 
     TrackedRendererListHashSet* positionedObjects() const;
     bool hasPositionedObjects() const
     {
         TrackedRendererListHashSet* objects = positionedObjects();
         return objects && !objects->isEmpty();
     }
 
+    virtual bool visibleToHitTestRequest(const HitTestRequest& request) const
+    {
+        if (request.touchAction())
+            return style()->visibility() == VISIBLE && style()->pointerEvents() != PE_NONE && !isInert();

[Rick Byers, 2014/02/17 14:43:52]

The general approach of updating visibleToHitTestRequest and making it vritual
seems good to me, thanks!  But it's unfortunate to have to duplicate the normal
(not-touch-action-related) hit test logic in RenderObject, RenderBlock, and
RenderSVGRoot.

How about having the derived functions pass a modified HitTestRequest to the
base that clears the touch action flag?  I.e.

// Touch action hit tests on a RenderBlock are done exactly like normal hit
tests
if (request.touchAction())
  RenderObject::visibleToHitTestRequest(HitTestRequest(request.type() &
~TouchAction);

What do you think?

[gnana, 2014/02/24 18:59:50]

This looks better. modified
Done.

+        return RenderObject::visibleToHitTestRequest(request);
+    }
+
     void addPercentHeightDescendant(RenderBox*);
     static void removePercentHeightDescendant(RenderBox*);
     static bool hasPercentHeightContainerMap();
     static bool hasPercentHeightDescendant(RenderBox*);
     static void clearPercentHeightDescendantsFrom(RenderBox*);
     static void removePercentHeightDescendantIfNeeded(RenderBox*);
 
     TrackedRendererListHashSet* percentHeightDescendants() const;
     bool hasPercentHeightDescendants() const
     {
@@ skipping 507 matching lines @@
             return false;
     }
     return true;
 }
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderBlock, isRenderBlock());
 
 } // namespace WebCore
 
 #endif // RenderBlock_h