Support subpixel layout for borders.

third_party/WebKit/Source/core/layout/api/LayoutBoxModel.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 LayoutBoxModel_h
 #define LayoutBoxModel_h
 
 #include "core/layout/LayoutBoxModelObject.h"
 #include "core/layout/api/LayoutItem.h"
 
@@ skipping 13 matching lines @@
   explicit LayoutBoxModel(std::nullptr_t) : LayoutItem(nullptr) {}
 
   LayoutBoxModel() {}
 
   PaintLayer* layer() const { return toBoxModel()->layer(); }
 
   PaintLayerScrollableArea* getScrollableArea() const {
     return toBoxModel()->getScrollableArea();
   }
 
-  int borderTop() const { return toBoxModel()->borderTop(); }
+  LayoutUnit borderTop() const { return toBoxModel()->borderTop(); }
 
-  int borderLeft() const { return toBoxModel()->borderLeft(); }
+  LayoutUnit borderLeft() const { return toBoxModel()->borderLeft(); }
 
   LayoutUnit paddingTop() const { return toBoxModel()->paddingTop(); }
 
   LayoutUnit paddingLeft() const { return toBoxModel()->paddingLeft(); }
 
  private:
   LayoutBoxModelObject* toBoxModel() {
     return toLayoutBoxModelObject(layoutObject());
   }
   const LayoutBoxModelObject* toBoxModel() const {
     return toLayoutBoxModelObject(layoutObject());
   }
 };
 
 }  // namespace blink
 
 #endif  // LayoutBoxModel_h