Make ElementShadow::oldestShadowRoot() return a reference

third_party/WebKit/Source/core/dom/Element.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 2101 matching lines @@
 {
     ShadowRoot* root = shadowRoot();
     if (!root)
         return nullptr;
     return root->type() != ShadowRootType::UserAgent ? root : nullptr;
 }
 
 ShadowRoot* Element::userAgentShadowRoot() const
 {
     if (ElementShadow* elementShadow = shadow()) {
-        if (ShadowRoot* root = elementShadow->oldestShadowRoot()) {
-            DCHECK(root->type() == ShadowRootType::UserAgent);
-            return root;
-        }
+        ShadowRoot& root = elementShadow->oldestShadowRoot();
+        DCHECK(root.type() == ShadowRootType::UserAgent);
+        return &root;
     }
 
     return nullptr;
 }
 
 ShadowRoot& Element::ensureUserAgentShadowRoot()
 {
     if (ShadowRoot* shadowRoot = userAgentShadowRoot())
         return *shadowRoot;
     ShadowRoot& shadowRoot = ensureShadow().addShadowRoot(*this, ShadowRootType::UserAgent);
@@ skipping 1682 matching lines @@
 
 DEFINE_TRACE_WRAPPERS(Element)
 {
     if (hasRareData()) {
         visitor->traceWrappers(elementRareData());
     }
     ContainerNode::traceWrappers(visitor);
 }
 
 } // namespace blink