Make ElementShadow::youngestShadowRoot() return a reference

third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp

Index: third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp
diff --git a/third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp b/third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp
index dd1ec1e8d8c81e2fb8b27cf5a7c3c0f4fc475fc0..319d6f4e2d7b33961b020b0722d78e7962a8a3f2 100644
--- a/third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp
+++ b/third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp
@@ -131,7 +131,7 @@ static void collectScopedResolversForHostedShadowTrees(const Element* element, W
         return;
 
     // Adding scoped resolver for active shadow roots for shadow host styling.
-    for (ShadowRoot* shadowRoot = shadow->youngestShadowRoot(); shadowRoot; shadowRoot = shadowRoot->olderShadowRoot()) {
+    for (ShadowRoot* shadowRoot = &shadow->youngestShadowRoot(); shadowRoot; shadowRoot = shadowRoot->olderShadowRoot()) {
         if (shadowRoot->numberOfStyles() > 0) {
             if (ScopedStyleResolver* resolver = shadowRoot->scopedStyleResolver())
                 resolvers.append(resolver);