Have Element::ensureMutableInlineStyle() return a reference

Source/core/page/PageSerializer.cpp

Index: Source/core/page/PageSerializer.cpp
diff --git a/Source/core/page/PageSerializer.cpp b/Source/core/page/PageSerializer.cpp
index c596260732a2e73218fff48592e2426e43b205eb..0da6c5c6409f7f48e29f7b90f158a85b39761334 100644
--- a/Source/core/page/PageSerializer.cpp
+++ b/Source/core/page/PageSerializer.cpp
@@ -276,9 +276,9 @@ void PageSerializer::serializeCSSStyleSheet(CSSStyleSheet* styleSheet, const KUR
                 continue;
             serializeCSSStyleSheet(importRule->styleSheet(), importURL);
         } else if (rule->type() == CSSRule::FONT_FACE_RULE) {
-            retrieveResourcesForProperties(toCSSFontFaceRule(rule)->styleRule()->properties(), document);
+            retrieveResourcesForProperties(&toCSSFontFaceRule(rule)->styleRule()->properties(), document);
         } else if (rule->type() == CSSRule::STYLE_RULE) {
-            retrieveResourcesForProperties(toCSSStyleRule(rule)->styleRule()->properties(), document);
+            retrieveResourcesForProperties(&toCSSStyleRule(rule)->styleRule()->properties(), document);
         }
     }