Have Document::elementSheet() return a reference

Source/core/dom/Element.cpp

Index: Source/core/dom/Element.cpp
diff --git a/Source/core/dom/Element.cpp b/Source/core/dom/Element.cpp
index d4b04d89625d2395483c934aa7fddb92f94c807d..b2e15a9932dd665006270c105e07fef4d5d01e81 100644
--- a/Source/core/dom/Element.cpp
+++ b/Source/core/dom/Element.cpp
@@ -3355,7 +3355,7 @@ inline void Element::setInlineStyleFromString(const AtomicString& newStyleString
         inlineStyle = BisonCSSParser::parseInlineStyleDeclaration(newStyleString, this);
     } else {
         ASSERT(inlineStyle->isMutable());
-        static_pointer_cast<MutableStylePropertySet>(inlineStyle)->parseDeclaration(newStyleString, document().elementSheet()->contents());
+        static_pointer_cast<MutableStylePropertySet>(inlineStyle)->parseDeclaration(newStyleString, document().elementSheet().contents());
     }
 }
 
@@ -3414,7 +3414,7 @@ bool Element::setInlineStyleProperty(CSSPropertyID propertyID, double value, CSS
 bool Element::setInlineStyleProperty(CSSPropertyID propertyID, const String& value, bool important)
 {
     ASSERT(isStyledElement());
-    bool changes = ensureMutableInlineStyle()->setProperty(propertyID, value, important, document().elementSheet()->contents());
+    bool changes = ensureMutableInlineStyle()->setProperty(propertyID, value, important, document().elementSheet().contents());
     if (changes)
         inlineStyleChanged();
     return changes;