[layoutng] Margin support, part 1

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"
 
 namespace blink {
 class ComputedStyle;
 class LayoutUnit;
 class Length;
 class NGConstraintSpace;
+struct NGBoxMargins;
 
-enum class LengthResolveType { MinSize, MaxSize, ContentSize };
+enum class LengthResolveType { MinSize, MaxSize, ContentSize, MarginSize };
 
 // Convert an inline-axis length to a layout unit using the given constraint
 // space.
 CORE_EXPORT LayoutUnit resolveInlineLength(const NGConstraintSpace&,
                                            const Length&,
                                            LengthResolveType);
 
 // Convert a block-axis length to a layout unit using the given constraint
 // space and content size.
 CORE_EXPORT LayoutUnit resolveBlockLength(const NGConstraintSpace&,
                                           const Length&,
                                           LayoutUnit contentSize,
                                           LengthResolveType);
 
 // Resolves the given length to a layout unit, constraining it by the min
 // logical width and max logical width properties from the ComputedStyle
 // object.
 CORE_EXPORT LayoutUnit computeInlineSizeForFragment(const NGConstraintSpace&,
                                                     const ComputedStyle&);
 
 // Resolves the given length to a layout unit, constraining it by the min
 // logical height and max logical height properties from the ComputedStyle
 // object.
 CORE_EXPORT LayoutUnit computeBlockSizeForFragment(const NGConstraintSpace&,
-                                                   const ComputedStyle& style,
+                                                   const ComputedStyle&,
                                                    LayoutUnit contentSize);
 
+CORE_EXPORT NGBoxMargins computeMargins(const NGConstraintSpace&,
+                                        const ComputedStyle&);
+
 }  // namespace blink
 
 #endif  // NGLengthUtils_h