Rewrite references to "wtf/" to "platform/wtf/" in core/layout.

third_party/WebKit/Source/core/layout/ng/ng_length_utils.h

 // 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 NGLengthUtils_h
 #define NGLengthUtils_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/geometry/ng_box_strut.h"
 #include "core/layout/ng/ng_min_max_content_size.h"
 #include "core/layout/ng/ng_writing_mode.h"
 #include "platform/text/TextDirection.h"
-#include "wtf/Optional.h"
+#include "platform/wtf/Optional.h"
 
 namespace blink {
 class ComputedStyle;
 class LayoutUnit;
 class Length;
 struct MinMaxContentSize;
 class NGConstraintSpace;
 struct NGBoxStrut;
 
 enum class LengthResolveType {
@@ skipping 96 matching lines @@
                                   const LayoutUnit& inline_size,
                                   NGBoxStrut* margins);
 
 CORE_EXPORT LayoutUnit ConstrainByMinMax(LayoutUnit length,
                                          Optional<LayoutUnit> min,
                                          Optional<LayoutUnit> max);
 
 }  // namespace blink
 
 #endif  // NGLengthUtils_h