[css-grid] Remove unneeded line in GridTrackSizingAlgorithm

third_party/WebKit/Source/core/layout/GridTrackSizingAlgorithm.h

 // Copyright 2017 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 GridTrackSizingAlgorithm_h
 #define GridTrackSizingAlgorithm_h
 
 #include <memory>
 #include "core/layout/LayoutBox.h"
 #include "core/style/GridPositionsResolver.h"
 #include "core/style/GridTrackSize.h"
 #include "platform/LayoutUnit.h"
 #include "platform/wtf/HashSet.h"
 #include "platform/wtf/Optional.h"
 
 namespace blink {
 
 static const int kInfinity = -1;
 
 class Grid;
 class GridTrackSizingAlgorithmStrategy;
 class LayoutGrid;
 
-enum MarginDirection;
-
 enum SizingOperation { kTrackSizing, kIntrinsicSizeComputation };
 
 enum TrackSizeComputationPhase {
   kResolveIntrinsicMinimums,
   kResolveContentBasedMinimums,
   kResolveMaxContentMinimums,
   kResolveIntrinsicMaximums,
   kResolveMaxContentMaximums,
   kMaximizeTracks,
 };
@@ skipping 260 matching lines @@
   static GridTrackSizingDirection FlowAwareDirectionForChild(
       const LayoutGrid*,
       const LayoutBox& child,
       GridTrackSizingDirection);
 
   GridTrackSizingAlgorithm& algorithm_;
 };
 }
 
 #endif  // GridTrackSizingAlgorithm_h