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

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

Index: third_party/WebKit/Source/core/layout/HitTestResult.cpp
diff --git a/third_party/WebKit/Source/core/layout/HitTestResult.cpp b/third_party/WebKit/Source/core/layout/HitTestResult.cpp
index 0e4ce899159275281c484bd0309a996356c2d400..e22a1971f0290a979f81faaa42f3f3a52e978900 100644
--- a/third_party/WebKit/Source/core/layout/HitTestResult.cpp
+++ b/third_party/WebKit/Source/core/layout/HitTestResult.cpp
@@ -172,8 +172,14 @@ LayoutObject* HitTestResult::layoutObject() const {
 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());
+      }
     }
   }
 }