Use IdTargetObserver in SVGUseElement

third_party/WebKit/Source/core/svg/SVGURIReference.h

Index: third_party/WebKit/Source/core/svg/SVGURIReference.h
diff --git a/third_party/WebKit/Source/core/svg/SVGURIReference.h b/third_party/WebKit/Source/core/svg/SVGURIReference.h
index 83887b19f24da6065d69b687139e694e84b0a20f..c25314b4fa27dbd562d667a9513f75ac5117e0af 100644
--- a/third_party/WebKit/Source/core/svg/SVGURIReference.h
+++ b/third_party/WebKit/Source/core/svg/SVGURIReference.h
@@ -23,13 +23,13 @@
 
 #include <memory>
 #include "core/CoreExport.h"
-#include "core/dom/Document.h"
 #include "core/svg/SVGAnimatedHref.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Functional.h"
 
 namespace blink {
 
+class Document;
 class Element;
 class IdTargetObserver;
 
@@ -61,6 +61,12 @@ class CORE_EXPORT SVGURIReference : public GarbageCollectedMixin {
   // |contextElement|.) Will call buildPendingResource() on |contextElement|
   // when changes to the 'id' are noticed.
   Element* observeTarget(Member<IdTargetObserver>&, SVGElement&);
+  // Create an 'id' observer for |id| in the specified TreeScope. On changes,
+  // the passed Closure will be called.
+  static Element* observeTarget(Member<IdTargetObserver>&,
+                                TreeScope&,
+                                const AtomicString& id,
+                                std::unique_ptr<WTF::Closure>);
   // Unregister and destroy the observer.
   static void unobserveTarget(Member<IdTargetObserver>&);