Fix textpath is not displayed on use element

third_party/WebKit/Source/core/svg/SVGTextPathElement.cpp

Index: third_party/WebKit/Source/core/svg/SVGTextPathElement.cpp
diff --git a/third_party/WebKit/Source/core/svg/SVGTextPathElement.cpp b/third_party/WebKit/Source/core/svg/SVGTextPathElement.cpp
index 3f889162dbd379bbb79f0cd78d6b9e386d4dafe7..897a64a8967d70435bf95378d01fae0e049b1c05 100644
--- a/third_party/WebKit/Source/core/svg/SVGTextPathElement.cpp
+++ b/third_party/WebKit/Source/core/svg/SVGTextPathElement.cpp
@@ -124,7 +124,16 @@ void SVGTextPathElement::buildPendingResource()
         return;
 
     AtomicString id;
-    Element* target = SVGURIReference::targetElementFromIRIString(hrefString(), treeScope(), &id);
+    Element* target = nullptr;
+
+    if (inUseShadowTree()) {

[fs, 2016/03/14 12:54:10]

Not sure this is actually needed. When the "real" element changes it will notify
the instance - which will then update. If anything we should probably just do
nothing here if this is an instance...

[hyunjunekim2, 2016/03/15 23:11:32]

Change before.

+        SVGElement* correspondingElement = this->correspondingElement();
+        if (correspondingElement)
+            target = SVGURIReference::targetElementFromIRIString(hrefString(), correspondingElement->treeScope(), &id);
+    } else {
+        target = SVGURIReference::targetElementFromIRIString(hrefString(), treeScope(), &id);
+    }
+
     if (!target) {
         // Do not register as pending if we are already pending this resource.
         if (document().accessSVGExtensions().isElementPendingResource(this, id))