[LayoutNG] Split LayoutOpportunityIterator into separate file

third_party/WebKit/Source/core/layout/ng/ng_constraint_space.h

Index: third_party/WebKit/Source/core/layout/ng/ng_constraint_space.h
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_constraint_space.h b/third_party/WebKit/Source/core/layout/ng/ng_constraint_space.h
index 88b5cfd535bac64d6fc34fe8ae0af2e6179b40e3..4662a766d9c3fd4c3f1c3c01cc7d221e28c27453 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_constraint_space.h
+++ b/third_party/WebKit/Source/core/layout/ng/ng_constraint_space.h
@@ -16,7 +16,6 @@
 namespace blink {
 
 class LayoutBox;
-class NGDerivedConstraintSpace;
 class NGFragment;
 class NGLayoutOpportunityIterator;
 
@@ -120,40 +119,6 @@ class CORE_EXPORT NGConstraintSpace final
   unsigned writing_mode_ : 3;
 };
 
-class CORE_EXPORT NGLayoutOpportunityIterator final
-    : public GarbageCollectedFinalized<NGLayoutOpportunityIterator> {
- public:
-  NGLayoutOpportunityIterator(NGConstraintSpace* space,
-                              unsigned clear,
-                              bool for_inline_or_bfc);
-  ~NGLayoutOpportunityIterator() {}
-
-  NGConstraintSpace* Next();
-
-  DEFINE_INLINE_VIRTUAL_TRACE() {
-    visitor->trace(constraint_space_);
-    visitor->trace(current_opportunities_);
-  }
-
- private:
-  void computeForExclusion(unsigned index);
-  LayoutUnit heightForOpportunity(LayoutUnit left,
-                                  LayoutUnit top,
-                                  LayoutUnit right,
-                                  LayoutUnit bottom);
-  void addLayoutOpportunity(LayoutUnit left,
-                            LayoutUnit top,
-                            LayoutUnit right,
-                            LayoutUnit bottom);
-
-  Member<NGConstraintSpace> constraint_space_;
-  unsigned clear_;
-  bool for_inline_or_bfc_;
-  Vector<NGExclusion> filtered_exclusions_;
-  HeapVector<Member<NGConstraintSpace>> current_opportunities_;
-  unsigned current_exclusion_idx_;
-};
-
 inline std::ostream& operator<<(std::ostream& stream,
                                 const NGConstraintSpace& value) {
   return stream << value.toString();