1 files changed, 37 insertions, 0 deletions
diff --git a/chromium/third_party/blink/renderer/core/layout/layout_block_flow.cc b/chromium/third_party/blink/renderer/core/layout/layout_block_flow.cc
index 6c5b8516a05..1568f9c8f06 100644
--- a/chromium/third_party/blink/renderer/core/layout/layout_block_flow.cc
+++ b/chromium/third_party/blink/renderer/core/layout/layout_block_flow.cc
@@ -55,6 +55,7 @@
 #include "third_party/blink/renderer/core/layout/line/line_width.h"
 #include "third_party/blink/renderer/core/layout/logical_values.h"
 #include "third_party/blink/renderer/core/layout/ng/inline/ng_line_height_metrics.h"
+#include "third_party/blink/renderer/core/layout/ng/inline/ng_offset_mapping.h"
 #include "third_party/blink/renderer/core/layout/ng/layout_ng_block_flow.h"
 #include "third_party/blink/renderer/core/layout/ng/legacy_layout_tree_walking.h"
 #include "third_party/blink/renderer/core/layout/ng/ng_absolute_utils.h"
@@ -446,6 +447,9 @@ void LayoutBlockFlow::UpdateBlockLayout(bool relayout_children) {
   if (RuntimeEnabledFeatures::TrackLayoutPassesPerBlockEnabled())
     IncrementLayoutPassCount();
 
+  if (rare_data_)
+    ClearOffsetMapping();
+
   if (!relayout_children && SimplifiedLayout())
     return;
 
@@ -4943,4 +4947,37 @@ int LayoutBlockFlow::GetLayoutPassCountForTesting() {
   return GetLayoutPassCountMap().find(this)->value;
 }
 
+LayoutBlockFlow::LayoutBlockFlowRareData::LayoutBlockFlowRareData(
+    const LayoutBlockFlow* block)
+    : margins_(PositiveMarginBeforeDefault(block),
+               NegativeMarginBeforeDefault(block),
+               PositiveMarginAfterDefault(block),
+               NegativeMarginAfterDefault(block)),
+      break_before_(static_cast<unsigned>(EBreakBetween::kAuto)),
+      break_after_(static_cast<unsigned>(EBreakBetween::kAuto)),
+      line_break_to_avoid_widow_(-1),
+      did_break_at_line_to_avoid_widow_(false),
+      discard_margin_before_(false),
+      discard_margin_after_(false) {}
+
+LayoutBlockFlow::LayoutBlockFlowRareData::~LayoutBlockFlowRareData() = default;
+
+void LayoutBlockFlow::ClearOffsetMapping() {
+  DCHECK(!IsLayoutNGObject());
+  DCHECK(rare_data_);
+  rare_data_->offset_mapping_.reset();
+}
+
+const NGOffsetMapping* LayoutBlockFlow::GetOffsetMapping() const {
+  DCHECK(!IsLayoutNGObject());
+  return rare_data_ ? rare_data_->offset_mapping_.get() : nullptr;
+}
+
+void LayoutBlockFlow::SetOffsetMapping(
+    std::unique_ptr<NGOffsetMapping> offset_mapping) {
+  DCHECK(!IsLayoutNGObject());
+  DCHECK(offset_mapping);
+  EnsureRareData().offset_mapping_ = std::move(offset_mapping);
+}
+
 }  // namespace blink