1 files changed, 46 insertions, 0 deletions
diff --git a/layout/style/DocumentStyleRootIterator.cpp b/layout/style/DocumentStyleRootIterator.cpp
new file mode 100644
index 0000000000..7e58a66f86
--- /dev/null
+++ b/layout/style/DocumentStyleRootIterator.cpp
@@ -0,0 +1,46 @@
+/* -*- 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/. */
+
+#include "DocumentStyleRootIterator.h"
+
+#include "mozilla/dom/Element.h"
+#include "nsContentUtils.h"
+
+namespace mozilla {
+
+DocumentStyleRootIterator::DocumentStyleRootIterator(nsINode* aStyleRoot)
+    : mPosition(0) {
+  MOZ_COUNT_CTOR(DocumentStyleRootIterator);
+  MOZ_ASSERT(aStyleRoot);
+  if (aStyleRoot->IsElement()) {
+    mStyleRoots.AppendElement(aStyleRoot->AsElement());
+    return;
+  }
+
+  dom::Document* doc = aStyleRoot->OwnerDoc();
+  MOZ_ASSERT(doc == aStyleRoot);
+  if (dom::Element* root = doc->GetRootElement()) {
+    mStyleRoots.AppendElement(root);
+  }
+  nsContentUtils::AppendDocumentLevelNativeAnonymousContentTo(doc, mStyleRoots);
+}
+
+dom::Element* DocumentStyleRootIterator::GetNextStyleRoot() {
+  for (;;) {
+    if (mPosition >= mStyleRoots.Length()) {
+      return nullptr;
+    }
+
+    nsIContent* next = mStyleRoots[mPosition];
+    ++mPosition;
+
+    if (next->IsElement()) {
+      return next->AsElement();
+    }
+  }
+}
+
+}  // namespace mozilla