1 files changed, 53 insertions, 0 deletions
diff --git a/chromium/third_party/blink/renderer/core/layout/ng/ng_flex_child_iterator.h b/chromium/third_party/blink/renderer/core/layout/ng/ng_flex_child_iterator.h
new file mode 100644
index 00000000000..609483fc790
--- /dev/null
+++ b/chromium/third_party/blink/renderer/core/layout/ng/ng_flex_child_iterator.h
@@ -0,0 +1,53 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_NG_NG_FLEX_CHILD_ITERATOR_H_
+#define THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_NG_NG_FLEX_CHILD_ITERATOR_H_
+
+#include "third_party/blink/renderer/core/core_export.h"
+#include "third_party/blink/renderer/core/layout/ng/ng_block_node.h"
+#include "third_party/blink/renderer/platform/wtf/vector.h"
+
+namespace blink {
+
+// A utility class for flex layout which given the current node will iterate
+// through its children.
+//
+// TODO(layout-dev): Once flex layout supports NG-fragmentation this will need
+// to be updated to accept a break-token.
+//
+// This class does not handle modifications to its arguments after it has been
+// constructed.
+class CORE_EXPORT NGFlexChildIterator {
+  STACK_ALLOCATED();
+
+ public:
+  NGFlexChildIterator(const NGBlockNode node);
+
+  // Returns the next block node which should be laid out.
+  NGBlockNode NextChild() {
+    if (iterator_ == children_.end())
+      return nullptr;
+
+    return (*iterator_++).child;
+  }
+
+  struct ChildWithOrder {
+    DISALLOW_NEW();
+    ChildWithOrder(NGBlockNode child, int order) : child(child), order(order) {}
+    NGBlockNode child;
+    int order;
+  };
+
+ private:
+  Vector<ChildWithOrder, 4> children_;
+  Vector<ChildWithOrder, 4>::const_iterator iterator_;
+};
+
+}  // namespace blink
+
+WTF_ALLOW_MOVE_AND_INIT_WITH_MEM_FUNCTIONS(
+    blink::NGFlexChildIterator::ChildWithOrder)
+
+#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_NG_NG_FLEX_CHILD_ITERATOR_H_