Turn StyleSharing to 11.

sky/engine/core/dom/TreeScope.cpp

Index: sky/engine/core/dom/TreeScope.cpp
diff --git a/sky/engine/core/dom/TreeScope.cpp b/sky/engine/core/dom/TreeScope.cpp
index 446fc244d49a66d4aaed9e8f7a53ff8b0c68bd81..b4cd28df9e8f01fa2a1bb1c9b842f8a38dc6f5ef 100644
--- a/sky/engine/core/dom/TreeScope.cpp
+++ b/sky/engine/core/dom/TreeScope.cpp
@@ -28,6 +28,7 @@
 #include "sky/engine/core/dom/TreeScope.h"
 
 #include "gen/sky/core/HTMLNames.h"
+#include "sky/engine/core/css/StyleSheetList.h"
 #include "sky/engine/core/css/resolver/ScopedStyleResolver.h"
 #include "sky/engine/core/dom/ContainerNode.h"
 #include "sky/engine/core/dom/Document.h"
@@ -420,4 +421,22 @@ void TreeScope::setNeedsStyleRecalcForViewportUnits()
     }
 }
 
+bool TreeScope::hasSameStyles(TreeScope& other)
+{
+    if (this == &other)
+        return true;
+    const Vector<RefPtr<blink::CSSStyleSheet> >& list = document().styleEngine()->styleSheetsForStyleSheetList(*this);
+    const Vector<RefPtr<blink::CSSStyleSheet> >& otherList = document().styleEngine()->styleSheetsForStyleSheetList(other);
+
+    if (list.size() != otherList.size())
+        return false;
+
+    for (size_t i = 0; i < list.size(); i++) {
+        if (list[i]->contents() != otherList[i]->contents())
+            return false;
+    }
+
+    return true;
+}
+
 } // namespace blink