[LayoutNG] Abort a layout once the BFC offset is resolved.

third_party/WebKit/Source/core/layout/ng/ng_constraint_space.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 NGConstraintSpace_h
 #define NGConstraintSpace_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/geometry/ng_logical_offset.h"
 #include "core/layout/ng/geometry/ng_logical_size.h"
@@ skipping 129 matching lines @@
   //
   // This value should be propogated to child layouts if the current layout
   // hasn't resolved its BFC offset yet.
   //
   // This value is calculated *after* an initial pass of the tree, this value
   // should only be present during the second pass.
   WTF::Optional<NGLogicalOffset> FloatsBfcOffset() const {
     return floats_bfc_offset_;
   }
 
-  Vector<RefPtr<NGUnpositionedFloat>>& UnpositionedFloats() {
+  const Vector<RefPtr<NGUnpositionedFloat>>& UnpositionedFloats() const {
     return unpositioned_floats_;
   }
 
   WTF::Optional<LayoutUnit> ClearanceOffset() const {
     return clearance_offset_;
   }
 
   bool operator==(const NGConstraintSpace&) const;
   bool operator!=(const NGConstraintSpace&) const;
 
@@ skipping 62 matching lines @@
 };
 
 inline std::ostream& operator<<(std::ostream& stream,
                                 const NGConstraintSpace& value) {
   return stream << value.ToString();
 }
 
 }  // namespace blink
 
 #endif  // NGConstraintSpace_h