Expose Document::isPrivilegedContext from WebDocument

Source/web/WebDocument.cpp

Index: Source/web/WebDocument.cpp
diff --git a/Source/web/WebDocument.cpp b/Source/web/WebDocument.cpp
index 1cfc8aebb9ab90835b1d357ad7cae1318aba3c46..b6a2c65a298b60d9c6e10931a9e1a8d3b8b8c760 100644
--- a/Source/web/WebDocument.cpp
+++ b/Source/web/WebDocument.cpp
@@ -82,6 +82,17 @@ WebSecurityOrigin WebDocument::securityOrigin() const
     return WebSecurityOrigin(constUnwrap<Document>()->securityOrigin());
 }
 
+bool WebDocument::isPrivilegedContext(WebString& errorMessage) const
+{
+    const Document* document = constUnwrap<Document>();
+    if (!document)
+        return false;
+    String message;
+    bool result = document->isPrivilegedContext(message);
+    errorMessage = message;
+    return result;
+}
+
 WebString WebDocument::encoding() const
 {
     return constUnwrap<Document>()->encodingName();