Change the type of a SVG <use> element's shadow tree from "user agent" to "closed"

third_party/WebKit/Source/core/layout/HitTestResult.cpp

 /*
  * Copyright (C) 2006, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies)
  *
  * 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 151 matching lines @@
       m_innerPossiblyPseudoNode->getPseudoId() == PseudoIdBefore)
     return mostForwardCaretPosition(
         Position(m_innerNode, PositionAnchorType::BeforeChildren));
   return layoutObject->positionForPoint(localPoint());
 }
 
 LayoutObject* HitTestResult::layoutObject() const {
   return m_innerNode ? m_innerNode->layoutObject() : 0;
 }
 
 void HitTestResult::setToShadowHostIfInUserAgentShadowRoot() {

[fs, 2017/03/15 13:34:45]

Maybe the method name should be updated to reflect that it no longer only
operates on only UA shadow roots? (setToShadowHostIfInRestrictedShadowRoot or
something maybe?)

[hayato, 2017/03/16 03:57:33]

Done

   if (Node* node = innerNode()) {
     if (ShadowRoot* containingShadowRoot = node->containingShadowRoot()) {
-      if (containingShadowRoot->type() == ShadowRootType::UserAgent)
+      if (containingShadowRoot->type() == ShadowRootType::UserAgent) {
         setInnerNode(node->ownerShadowHost());
+      } else if (containingShadowRoot->type() == ShadowRootType::Closed &&
+                 isSVGUseElement(containingShadowRoot->host())) {
+        // Consider a closed shadow tree of SVG's <use> element as a special
+        // case. A toolip does not work in svg's <use> element without this.

[fs, 2017/03/15 13:34:45]

Nit: tooltip, also svg's -> SVG's (for consistency; or rewrite to drop the
repetition [preferred])

[hayato, 2017/03/16 03:57:33]

Done. I have rewritten it to drop the repetition.

+        setInnerNode(node->ownerShadowHost());
+      }
     }
   }
 }
 
 HTMLAreaElement* HitTestResult::imageAreaForImage() const {
   ASSERT(m_innerNode);
   HTMLImageElement* imageElement = nullptr;
   if (isHTMLImageElement(m_innerNode)) {
     imageElement = toHTMLImageElement(m_innerNode);
   } else if (m_innerNode->isInShadowTree()) {
@@ skipping 316 matching lines @@
   else if (isHTMLMapElement(m_innerNode))
     imageMapImageElement = toHTMLMapElement(m_innerNode)->imageElement();
 
   if (!imageMapImageElement)
     return m_innerNode.get();
 
   return imageMapImageElement;
 }
 
 }  // namespace blink