Change hittest node to be scrollbar's parent when hittest include a scrollbar

third_party/WebKit/Source/core/layout/LayoutView.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.
  *
@@ skipping 137 matching lines @@
     // Layer::hitTestOverflowControls, so we need to test FrameView scrollbars
     // separately here. Note that it's important we do this after the hit test
     // above, because that may overwrite the entire HitTestResult when it finds
     // a hit.
     IntPoint framePoint =
         frameView()->contentsToFrame(result.hitTestLocation().roundedPoint());
     if (Scrollbar* frameScrollbar =
             frameView()->scrollbarAtFramePoint(framePoint))
       result.setScrollbar(frameScrollbar);
 
+    // If hitTestResult include scrollbar, innerNode should be the parent of the
+    // scrollbar.
+    if (result.scrollbar()) {
+      ScrollableArea* scrollableArea = result.scrollbar()->getScrollableArea();

[bokan, 2017/03/31 20:07:00]

We should probably clear the innerNode first. That way if we hit a scrollbar
whose scrollable area isn't associated with a LayoutBox we aren't hitting some
random element below too.

+      if (scrollableArea && scrollableArea->layoutBox() &&
+          scrollableArea->layoutBox()->node()) {
+        Node* node = scrollableArea->layoutBox()->node();
+        result.setInnerNode(node);
+        result.setURLElement(node->enclosingLinkEventParentOrSelf());

[mustaq, 2017/03/31 16:57:48]

Please add a comment for |HitTestResult.m_innerURLElement| to say that for
non-URL, it's the enclosing elem that triggers navigation.

+      }
+    }
+
     if (hitLayer)
       m_hitTestCache->addCachedResult(result, domTreeVersion);
   }
 
   TRACE_EVENT_END1(
       "blink,devtools.timeline", "HitTest", "endData",
       InspectorHitTestEvent::endData(result.hitTestRequest(),
                                      result.hitTestLocation(), result));
   return hitLayer;
 }
@@ skipping 908 matching lines @@
 bool LayoutView::paintedOutputOfObjectHasNoEffectRegardlessOfSize() const {
   // Frame scroll corner is painted using LayoutView as the display item client.
   if (!RuntimeEnabledFeatures::rootLayerScrollingEnabled() &&
       (frameView()->horizontalScrollbar() || frameView()->verticalScrollbar()))
     return false;
 
   return LayoutBlockFlow::paintedOutputOfObjectHasNoEffectRegardlessOfSize();
 }
 
 }  // namespace blink