Have Document::elementSheet() return a reference

Source/core/inspector/InspectorStyleSheet.cpp

Index: Source/core/inspector/InspectorStyleSheet.cpp
diff --git a/Source/core/inspector/InspectorStyleSheet.cpp b/Source/core/inspector/InspectorStyleSheet.cpp
index 789bf9c3136277b280ab8a0238b41aef7e645619..a5b7012eccb55b89a40df3743ef1f9eca9d1e19a 100644
--- a/Source/core/inspector/InspectorStyleSheet.cpp
+++ b/Source/core/inspector/InspectorStyleSheet.cpp
@@ -1739,8 +1739,8 @@ PassRefPtr<CSSRuleSourceData> InspectorStyleSheetForInlineStyle::getStyleAttribu
 
     RefPtr<MutableStylePropertySet> tempDeclaration = MutableStylePropertySet::create();
     RuleSourceDataList ruleSourceDataResult;
-    StyleSheetHandler handler(m_styleText, &m_element->document(), m_element->document().elementSheet()->contents(), &ruleSourceDataResult);
-    createCSSParser(&m_element->document())->parseDeclaration(tempDeclaration.get(), m_styleText, &handler, m_element->document().elementSheet()->contents());
+    StyleSheetHandler handler(m_styleText, &m_element->document(), m_element->document().elementSheet().contents(), &ruleSourceDataResult);
+    createCSSParser(&m_element->document())->parseDeclaration(tempDeclaration.get(), m_styleText, &handler, m_element->document().elementSheet().contents());
     return ruleSourceDataResult.first().release();
 }