[LayoutNG] Remove the ng_layout_coordinator and temporary LayoutSync method.

third_party/WebKit/Source/core/layout/ng/ng_legacy_block_layout_algorithm.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_legacy_block_layout_algorithm.h"
 
 #include "core/layout/ng/ng_physical_box_fragment.h"
 
 namespace blink {
 
 NGLegacyBlockLayoutAlgorithm::NGLegacyBlockLayoutAlgorithm(
     NGBlockNode* block,
     const NGConstraintSpace* constraint_space)
     : NGLayoutAlgorithm(kLegacyBlockLayoutAlgorithm),
       block_(block),
       constraint_space_(constraint_space) {}
 
-NGLayoutStatus NGLegacyBlockLayoutAlgorithm::Layout(
-    NGPhysicalFragment*,
-    NGPhysicalFragment** fragment_out,
-    NGLayoutAlgorithm**) {
-  *fragment_out = block_->RunOldLayout(*constraint_space_);
-  return kNewFragment;
+NGPhysicalFragment* NGLegacyBlockLayoutAlgorithm::Layout() {
+  return block_->RunOldLayout(*constraint_space_);
 }
 
 DEFINE_TRACE(NGLegacyBlockLayoutAlgorithm) {
   NGLayoutAlgorithm::trace(visitor);
   visitor->trace(block_);
   visitor->trace(constraint_space_);
 }
 }