Implement collection of out-of-flow descendants

third_party/WebKit/Source/core/layout/ng/ng_units.cc

Index: third_party/WebKit/Source/core/layout/ng/ng_units.cc
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_units.cc b/third_party/WebKit/Source/core/layout/ng/ng_units.cc
index 2e515a8c53e60806a6cae10ef86e47ff8be4b791..1de7f2ccf5515af748393c8ae28310a983c819c2 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_units.cc
+++ b/third_party/WebKit/Source/core/layout/ng/ng_units.cc
@@ -134,6 +134,16 @@ String NGLogicalOffset::ToString() const {
   return String::format("%dx%d", inline_offset.toInt(), block_offset.toInt());
 }
 
+NGPhysicalOffset NGPhysicalOffset::operator+(
+    const NGPhysicalOffset& other) const {
+  return NGPhysicalOffset{this->left + other.left, this->top + other.top};
+}
+
+NGPhysicalOffset& NGPhysicalOffset::operator+=(const NGPhysicalOffset& other) {
+  *this = *this + other;
+  return *this;
+}
+
 bool NGBoxStrut::IsEmpty() const {
   return *this == NGBoxStrut();
 }
@@ -226,4 +236,27 @@ bool NGMarginStrut::operator==(const NGMarginStrut& other) const {
                   negative_margin_block_start, negative_margin_block_end);
 }
 
+NGCorner NGCorner::Create(NGWritingMode writing_mode,
+                          TextDirection direction,
+                          NGPhysicalOffset offset) {
+  NGCorner c;
+  c.offset = offset;
+  switch (writing_mode) {
+    case kHorizontalTopBottom:
+      c.type = (direction == LTR) ? kTopLeft : kTopRight;
+      break;
+    case kVerticalRightLeft:
+    case kSidewaysRightLeft:
+      c.type = (direction == LTR) ? kTopRight : kBottomRight;
+      break;
+    case kVerticalLeftRight:
+      c.type = (direction == LTR) ? kTopLeft : kBottomLeft;
+      break;
+    case kSidewaysLeftRight:
+      c.type = (direction == LTR) ? kBottomLeft : kTopLeft;
+      break;
+  }
+  return c;
+}
+
 }  // namespace blink