SVG objects with same idrefs conflict when under different shadow root

third_party/WebKit/Source/core/dom/TreeScope.h

Index: third_party/WebKit/Source/core/dom/TreeScope.h
diff --git a/third_party/WebKit/Source/core/dom/TreeScope.h b/third_party/WebKit/Source/core/dom/TreeScope.h
index d43a3b721168b31a82a1efd5063e6b1b7e554a17..6b67e29adaadbc2c53b3c688422e1884136b1cab 100644
--- a/third_party/WebKit/Source/core/dom/TreeScope.h
+++ b/third_party/WebKit/Source/core/dom/TreeScope.h
@@ -43,6 +43,7 @@ class Element;
 class HTMLMapElement;
 class HitTestResult;
 class IdTargetObserverRegistry;
+class SVGTreeScopeResources;
 class ScopedStyleResolver;
 class Node;
 
@@ -127,6 +128,9 @@ class CORE_EXPORT TreeScope : public GarbageCollectedMixin {
   ScopedStyleResolver& ensureScopedStyleResolver();
   void clearScopedStyleResolver();
 
+  const SVGTreeScopeResources* svgExtensions();
+  SVGTreeScopeResources& accessSVGTreeScopedResources();

[pdr., 2017/01/23 04:34:12]

optional: ensureSVGTreeScopedResources so it's more obvious that this does work?

I'd be okay with leaving this for a followup, or not doing it at all on the
basis that the current code uses access*. Grepping around the codebase, ensure*
just seems to be preferred.

[fs, 2017/01/23 11:18:24]

I don't see why not - we're replacing all instances anyway so... Done. Dropped
the svgExtensions() method too since it wasn't used.

+
  protected:
   TreeScope(ContainerNode&, Document&);
   TreeScope(Document&);
@@ -151,6 +155,8 @@ class CORE_EXPORT TreeScope : public GarbageCollectedMixin {
   mutable Member<DOMSelection> m_selection;
 
   RadioButtonGroupScope m_radioButtonGroupScope;
+
+  Member<SVGTreeScopeResources> m_svgTreeScopedResources;
 };
 
 inline bool TreeScope::hasElementWithId(const AtomicString& id) const {