Fix textpath is not displayed on use element

third_party/WebKit/Source/core/layout/svg/LayoutSVGTextPath.cpp

Index: third_party/WebKit/Source/core/layout/svg/LayoutSVGTextPath.cpp
diff --git a/third_party/WebKit/Source/core/layout/svg/LayoutSVGTextPath.cpp b/third_party/WebKit/Source/core/layout/svg/LayoutSVGTextPath.cpp
index 5562e3959948812d8387b6f8ccf2951aa0f331ac..084bf3125facda179949a538cd29ca003a29af4e 100644
--- a/third_party/WebKit/Source/core/layout/svg/LayoutSVGTextPath.cpp
+++ b/third_party/WebKit/Source/core/layout/svg/LayoutSVGTextPath.cpp
@@ -60,8 +60,17 @@ bool LayoutSVGTextPath::isChildAllowed(LayoutObject* child, const ComputedStyle&
 PassOwnPtr<PathPositionMapper> LayoutSVGTextPath::layoutPath() const
 {
     const SVGTextPathElement& textPathElement = toSVGTextPathElement(*node());
-    Element* targetElement = SVGURIReference::targetElementFromIRIString(
-        textPathElement.hrefString(), textPathElement.treeScope());
+    Element* targetElement;
+    if (textPathElement.inUseShadowTree()) {

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

I think we could simplify this a bit (and preferably move it to a helper so that
we can pick one TreeScope& or the other:

TreeScope& treeScopeForIdResolution(SVGElement& element)
{
    if (SVGElement* correspondingElement = element.correspondingElement())
        return correspondingElement->treeScope();
    return element.treeScope();
}

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

Done.

+        SVGElement* correspondingElement = textPathElement.correspondingElement();
+        if (correspondingElement && isSVGTextPathElement(correspondingElement)) {
+            targetElement = SVGURIReference::targetElementFromIRIString(
+                textPathElement.hrefString(), correspondingElement->treeScope());
+        }
+    } else {
+        targetElement = SVGURIReference::targetElementFromIRIString(
+            textPathElement.hrefString(), textPathElement.treeScope());
+    }
     if (!isSVGPathElement(targetElement))
         return nullptr;