1 files changed, 45 insertions, 0 deletions
diff --git a/layout/style/DocumentStyleRootIterator.h b/layout/style/DocumentStyleRootIterator.h
new file mode 100644
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+++ b/layout/style/DocumentStyleRootIterator.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef DocumentStyleRootIterator_h
+#define DocumentStyleRootIterator_h
+
+#include "nsTArray.h"
+
+class nsIContent;
+
+class nsINode;
+
+namespace mozilla {
+
+namespace dom {
+class Element;
+}  // namespace dom
+
+/**
+ * DocumentStyleRootIterator traverses the roots of the document from the
+ * perspective of the Servo-backed style system. In the general case, this
+ * will first traverse the document root, followed by any document level
+ * native anonymous content.
+ *
+ * If the caller passes an element to the constructor rather than the document,
+ * that element (and nothing else) is returned from GetNextStyleRoot.
+ */
+class DocumentStyleRootIterator {
+ public:
+  explicit DocumentStyleRootIterator(nsINode* aStyleRoot);
+  MOZ_COUNTED_DTOR(DocumentStyleRootIterator)
+
+  dom::Element* GetNextStyleRoot();
+
+ private:
+  AutoTArray<nsIContent*, 8> mStyleRoots;
+  uint32_t mPosition;
+};
+
+}  // namespace mozilla
+
+#endif  // DocumentStyleRootIterator_h