Merge 133429 - Shadow DOM should be able to be disabled per context.

Source/WebCore/dom/ContextFeatures.cpp

Index: Source/WebCore/dom/ContextFeatures.cpp
===================================================================
--- Source/WebCore/dom/ContextFeatures.cpp	(revision 134364)
+++ Source/WebCore/dom/ContextFeatures.cpp	(working copy)
@@ -63,6 +63,18 @@
 #endif
 }
 
+bool ContextFeatures::shadowDOMEnabled(Document* document)
+{
+#if ENABLE(SHADOW_DOM)
+    if (!document)
+        return RuntimeEnabledFeatures::shadowDOMEnabled();
+    return document->contextFeatures()->isEnabled(document, ShadowDOM, RuntimeEnabledFeatures::shadowDOMEnabled());
+#else
+    UNUSED_PARAM(document);
+    return false;
+#endif
+}
+
 bool ContextFeatures::styleScopedEnabled(Document* document)
 {
 #if ENABLE(STYLE_SCOPED)