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

third_party/WebKit/Source/core/layout/ng/ng_length_utils.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_length_utils.h"
 
 #include "core/layout/ng/ng_constraint_space.h"
 #include "core/layout/ng/ng_constraint_space_builder.h"
 #include "core/layout/ng/ng_fragment.h"
 #include "core/style/ComputedStyle.h"
 #include "platform/LayoutUnit.h"
 #include "platform/Length.h"
-#include "wtf/Optional.h"
+#include "platform/wtf/Optional.h"
 
 namespace blink {
 // TODO(layout-ng):
 // - replaced calculations
 // - Take scrollbars into account
 
 bool NeedMinMaxContentSize(const NGConstraintSpace& constraint_space,
                            const ComputedStyle& style) {
   // This check is technically too broad (fill-available does not need intrinsic
   // size computation) but that's a rare case and only affects performance, not
@@ skipping 396 matching lines @@
                              Optional<LayoutUnit> min,
                              Optional<LayoutUnit> max) {
   if (max && length > max.value())
     length = max.value();
   if (min && length < min.value())
     length = min.value();
   return length;
 }
 
 }  // namespace blink