Add support of leader_point in NGLayoutOpportunityIterator.

third_party/WebKit/Source/core/layout/ng/ng_units.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 NGUnits_h
 #define NGUnits_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/ng_direction.h"
 #include "core/layout/ng/ng_writing_mode.h"
 #include "platform/LayoutUnit.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class LayoutUnit;
 struct NGPhysicalOffset;
 struct NGPhysicalSize;
 
 struct NGLogicalSize {
   NGLogicalSize() {}
   NGLogicalSize(LayoutUnit inline_size, LayoutUnit block_size)
       : inline_size(inline_size), block_size(block_size) {}
 
   LayoutUnit inline_size;
   LayoutUnit block_size;
 
   NGPhysicalSize ConvertToPhysical(NGWritingMode mode) const;
   bool operator==(const NGLogicalSize& other) const;
+
+  bool IsEmpty() const {
+    return inline_size == LayoutUnit(0) || block_size == LayoutUnit(0);

[cbiesinger, 2016/11/03 15:00:40]

Use LayoutUnit() instead of LayoutUnit(0)

Also, I wouldn't read the ToTT episode as avoiding negative booleans in all
circumstances. The guidelines in there are for different situations than what we
have here.

And I disagree with that LLVM link :)

[Gleb Lanbin, 2016/11/03 16:13:04]

Done.

+  }
 };
 
 // NGLogicalOffset is the position of a rect (typically a fragment) relative to
 // its parent rect in the logical coordinate system.
 struct NGLogicalOffset {
   NGLogicalOffset() {}
   NGLogicalOffset(LayoutUnit inline_offset, LayoutUnit block_offset)
       : inline_offset(inline_offset), block_offset(block_offset) {}
 
   LayoutUnit inline_offset;
   LayoutUnit block_offset;
 
   // Converts a logical offset to a physical offset. See:
   // https://drafts.csswg.org/css-writing-modes-3/#logical-to-physical
   // @param container_size the size of the rect (typically a fragment).
   // @param inner_size the size of the inner rect (typically a child fragment).
   CORE_EXPORT NGPhysicalOffset
   ConvertToPhysical(NGWritingMode mode,
                     NGDirection direction,
                     NGPhysicalSize container_size,
                     NGPhysicalSize inner_size) const;
   bool operator==(const NGLogicalOffset& other) const;
 
   NGLogicalOffset operator+(const NGLogicalOffset& other) const;
 
   NGLogicalOffset& operator+=(const NGLogicalOffset& other);
+
+  bool operator>(const NGLogicalOffset& other) const;
+  bool operator>=(const NGLogicalOffset& other) const;
+
+  bool operator<(const NGLogicalOffset& other) const;
+  bool operator<=(const NGLogicalOffset& other) const;
+
+  String ToString() const;
 };
 
+CORE_EXPORT inline std::ostream& operator<<(std::ostream& os,
+                                            const NGLogicalOffset& value) {
+  return os << value.ToString();
+}
+
 // NGPhysicalOffset is the position of a rect (typically a fragment) relative to
 // its parent rect in the physical coordinate system.
 struct NGPhysicalOffset {
   NGPhysicalOffset() {}
   NGPhysicalOffset(LayoutUnit left, LayoutUnit top) : left(left), top(top) {}
 
   LayoutUnit left;
   LayoutUnit top;
 };
 
@@ skipping 145 matching lines @@
 
 // Struct to represent a simple edge that has start and end.
 struct NGEdge {
   LayoutUnit start;
   LayoutUnit end;
 };
 
 }  // namespace blink
 
 #endif  // NGUnits_h