[LayoutNG] Move remaining ng_units structs to their own files

third_party/WebKit/Source/core/layout/ng/geometry/ng_edge.h

Index: third_party/WebKit/Source/core/layout/ng/geometry/ng_edge.h
diff --git a/third_party/WebKit/Source/core/layout/ng/geometry/ng_edge.h b/third_party/WebKit/Source/core/layout/ng/geometry/ng_edge.h
new file mode 100644
index 0000000000000000000000000000000000000000..062bc74674a7b485dee7ab300d7d955f502294f9
--- /dev/null
+++ b/third_party/WebKit/Source/core/layout/ng/geometry/ng_edge.h
@@ -0,0 +1,21 @@
+// Copyright 2016 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 NGEdge_h
+#define NGEdge_h
+
+#include "core/CoreExport.h"
+#include "platform/LayoutUnit.h"
+
+namespace blink {
+
+// Struct to represent a simple edge that has start and end.
+struct CORE_EXPORT NGEdge {
+  LayoutUnit start;
+  LayoutUnit end;
+};
+
+}  // namespace blink
+
+#endif  // NGEdge_h