[LayoutNG] Make NGBlockNode return a const style reference.

third_party/WebKit/Source/core/layout/ng/ng_layout_input_node.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_layout_input_node.h"
 
 #include "core/layout/ng/ng_block_layout_algorithm.h"
 #include "core/layout/ng/ng_block_node.h"
 #include "core/layout/ng/ng_constraint_space.h"
 #include "core/layout/ng/ng_inline_layout_algorithm.h"
 #include "core/layout/ng/ng_inline_node.h"
 #include "core/layout/ng/ng_layout_algorithm.h"
 #include "core/layout/ng/ng_legacy_block_layout_algorithm.h"
 #include "core/style/ComputedStyle.h"
 
 namespace blink {
 
 NGLayoutAlgorithm* NGLayoutInputNode::AlgorithmForInputNode(
     NGLayoutInputNode* input_node,
     NGConstraintSpace* constraint_space) {
   // At least for now, this should never be called on LegacyInline
   // children. However, there will be other kinds of input_node so
   // it makes sense to do this here.
   DCHECK(input_node->Type() == kLegacyBlock);
   NGBlockNode* block = toNGBlockNode(input_node);
   if (!block->CanUseNewLayout())
     return new NGLegacyBlockLayoutAlgorithm(block, constraint_space);
-  const ComputedStyle* style = block->Style();
+  const ComputedStyle& style = block->Style();
   LayoutObject* layout_object = input_node->GetLayoutObject();
   if (block->HasInlineChildren()) {
     NGInlineNode* child = toNGInlineNode(block->FirstChild());
-    return new NGInlineLayoutAlgorithm(layout_object, style, child,
+    return new NGInlineLayoutAlgorithm(layout_object, &style, child,
                                        constraint_space);
   }
   NGBlockNode* child = toNGBlockNode(block->FirstChild());
   // TODO(layout-ng): The break token should be passed as an argument to this
   // method instead of getting it from the NGBlockNode
   NGBreakToken* token = block->CurrentBreakToken();
-  return new NGBlockLayoutAlgorithm(layout_object, style, child,
+  return new NGBlockLayoutAlgorithm(layout_object, &style, child,
                                     constraint_space, token);
 }
 }