Hittest for RootInlineBox/InlineFlowBox should take care of border-radius.

Source/core/layout/line/InlineFlowBox.cpp

 /*
  * Copyright (C) 2003, 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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 957 matching lines @@
 }
 
 bool InlineFlowBox::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, LayoutUnit lineTop, LayoutUnit lineBottom)
 {
     LayoutRect overflowRect(visualOverflowRect(lineTop, lineBottom));
     flipForWritingMode(overflowRect);
     overflowRect.moveBy(accumulatedOffset);
     if (!locationInContainer.intersects(overflowRect))
         return false;
 
+    if (layoutObject().style()->hasBorderRadius()) {
+        LayoutRect borderRect = logicalFrameRect();
+        borderRect.moveBy(accumulatedOffset);
+        FloatRoundedRect border = layoutObject().style()->getRoundedBorderFor(borderRect, includeLogicalLeftEdge(), includeLogicalRightEdge());
+        if (!locationInContainer.intersects(border))

[davve, 2015/03/26 10:03:36]

We're heading in the right direction but it's still not quite there. We need to
consider nested inlines sticking out as well
(http://jsbin.com/bejevugilo/1/edit). BoxPainter::getBackgroundRoundedRect might
be a source of inspiration, but I don't like having to duplicate non-trivial
pieces of code. I might have to defer to an owner on the details here.

[Abhijeet Kandalkar Slow, 2015/03/27 11:28:59]

Added implementation to handle nested inlines and updated layout test too.

+            return false;
+    }
+
     // Check children first.
     // We need to account for culled inline parents of the hit-tested nodes, so that they may also get included in area-based hit-tests.
     LayoutObject* culledParent = 0;
     for (InlineBox* curr = lastChild(); curr; curr = curr->prevOnLine()) {
         if (curr->layoutObject().isText() || !curr->boxModelObject()->hasSelfPaintingLayer()) {
             LayoutObject* newParent = 0;
             // Culled parents are only relevant for area-based hit-tests, so ignore it in point-based ones.
             if (locationInContainer.isRectBasedTest()) {
                 newParent = curr->layoutObject().parent();
                 if (newParent == layoutObject())
@@ skipping 311 matching lines @@
         ASSERT(child->prevOnLine() == prev);
         prev = child;
     }
     ASSERT(prev == m_lastChild);
 #endif
 }
 
 #endif
 
 } // namespace blink