Revert of [LayoutNG] Move remaining ng_units structs to their own files

third_party/WebKit/Source/core/layout/ng/ng_min_max_content_size.cc

-// 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.
-
-#include "core/layout/ng/ng_min_max_content_size.h"
-
-namespace blink {
-
-LayoutUnit MinMaxContentSize::ShrinkToFit(LayoutUnit available_size) const {
-  DCHECK_GE(max_content, min_content);
-  return std::min(max_content, std::max(min_content, available_size));
-}
-
-bool MinMaxContentSize::operator==(const MinMaxContentSize& other) const {
-  return min_content == other.min_content && max_content == other.max_content;
-}
-
-std::ostream& operator<<(std::ostream& stream, const MinMaxContentSize& value) {
-  return stream << "(" << value.min_content << ", " << value.max_content << ")";
-}
-
-}  // namespace blink