Revert of Add support of leader_point in NGLayoutOpportunityIterator.

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

Index: third_party/WebKit/Source/core/layout/ng/ng_layout_opportunity_iterator.cc
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_layout_opportunity_iterator.cc b/third_party/WebKit/Source/core/layout/ng/ng_layout_opportunity_iterator.cc
index 01e6ba10222d43d1bfe00a2c9c8a49bdeaedf845..5eb1a7c78a601292445a6b44c4be74221492257c 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_layout_opportunity_iterator.cc
+++ b/third_party/WebKit/Source/core/layout/ng/ng_layout_opportunity_iterator.cc
@@ -150,10 +150,6 @@
 void InsertExclusion(NGLayoutOpportunityTreeNode* node,
                      const NGLogicalRect* exclusion,
                      NGLayoutOpportunities& opportunities) {
-  // Base case: size of the exclusion is empty.
-  if (exclusion->size.IsEmpty())
-    return;
-
   // Base case: there is no node.
   if (!node)
     return;
@@ -214,39 +210,13 @@
   return rhs.size.inline_size < lhs.size.inline_size;
 }
 
-void RunPreconditionChecks(const NGConstraintSpace& space,
-                           const NGLogicalOffset& origin_point,
-                           const NGLogicalOffset& leader_point) {
-  DCHECK_GE(origin_point, space.Offset())
-      << "Origin point" << origin_point
-      << " should lay below the constraint space's offset " << space.Offset();
-
-  DCHECK_GE(leader_point, space.Offset())
-      << "Leader point" << leader_point
-      << " should lay below the constraint space's offset " << space.Offset();
-}
-
-NGLogicalRect ToLeaderExclusion(const NGLogicalOffset& origin_point,
-                                const NGLogicalOffset& leader_point) {
-  LayoutUnit inline_size =
-      leader_point.inline_offset - origin_point.inline_offset;
-  LayoutUnit block_size = leader_point.block_offset - origin_point.block_offset;
-
-  NGLogicalRect leader_exclusion;
-  leader_exclusion.offset = origin_point;
-  leader_exclusion.size = {inline_size, block_size};
-  return leader_exclusion;
-}
-
 }  // namespace
 
 NGLayoutOpportunityIterator::NGLayoutOpportunityIterator(
     NGConstraintSpace* space,
-    const NGLogicalOffset& origin_point,
-    const NGLogicalOffset& leader_point)
-    : constraint_space_(space) {
-  RunPreconditionChecks(*space, origin_point, leader_point);
-
+    const NGLogicalOffset origin_point,
+    const NGLogicalOffset leader_point)
+    : constraint_space_(space), leader_point_(leader_point) {
   // TODO(chrome-layout-team): Combine exclusions that shadow each other.
   auto& exclusions = constraint_space_->PhysicalSpace()->Exclusions();
   DCHECK(std::is_sorted(exclusions.begin(), exclusions.end(),
@@ -256,11 +226,6 @@
   NGLayoutOpportunity initial_opportunity =
       CreateLayoutOpportunityFromConstraintSpace(*space, origin_point);
   opportunity_tree_root_ = new NGLayoutOpportunityTreeNode(initial_opportunity);
-
-  const NGLogicalRect leader_exclusion =
-      ToLeaderExclusion(origin_point, leader_point);
-  InsertExclusion(MutableOpportunityTreeRoot(), &leader_exclusion,
-                  opportunities_);
 
   for (const auto& exclusion : exclusions) {
     InsertExclusion(MutableOpportunityTreeRoot(), exclusion.get(),