Move LayoutBlockFlowRareData to Oilpan

Change-Id: I2ed7bec198b96a5533770da9987176205478bd69
Bug: 1030176
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1980521Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Commit-Queue: Navid Zolghadr <nzolghadr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#728402}

third_party/blink/renderer/core/layout/layout_block_flow.cc

@@ -77,7 +77,8 @@ bool LayoutBlockFlow::can_propagate_float_into_sibling_ = false;
 
 struct SameSizeAsLayoutBlockFlow : public LayoutBlock {
   LineBoxList line_boxes;
-  void* pointers[2];
+  void* pointers[1];
+  Persistent<void*> persistent[1];
 };
 
 static_assert(sizeof(LayoutBlockFlow) == sizeof(SameSizeAsLayoutBlockFlow),
@@ -2241,7 +2242,7 @@ void LayoutBlockFlow::SetMaxMarginBeforeValues(LayoutUnit pos, LayoutUnit neg) {
     if (pos == LayoutBlockFlowRareData::PositiveMarginBeforeDefault(this) &&
         neg == LayoutBlockFlowRareData::NegativeMarginBeforeDefault(this))
       return;
-    rare_data_ = std::make_unique<LayoutBlockFlowRareData>(this);
+    rare_data_ = MakeGarbageCollected<LayoutBlockFlowRareData>(this);
   }
   rare_data_->margins_.SetPositiveMarginBefore(pos);
   rare_data_->margins_.SetNegativeMarginBefore(neg);
@@ -2252,7 +2253,7 @@ void LayoutBlockFlow::SetMaxMarginAfterValues(LayoutUnit pos, LayoutUnit neg) {
     if (pos == LayoutBlockFlowRareData::PositiveMarginAfterDefault(this) &&
         neg == LayoutBlockFlowRareData::NegativeMarginAfterDefault(this))
       return;
-    rare_data_ = std::make_unique<LayoutBlockFlowRareData>(this);
+    rare_data_ = MakeGarbageCollected<LayoutBlockFlowRareData>(this);
   }
   rare_data_->margins_.SetPositiveMarginAfter(pos);
   rare_data_->margins_.SetNegativeMarginAfter(neg);
@@ -4193,7 +4194,7 @@ void LayoutBlockFlow::SetPaginationStrutPropagatedFromChild(LayoutUnit strut) {
   if (!rare_data_) {
     if (!strut)
       return;
-    rare_data_ = std::make_unique<LayoutBlockFlowRareData>(this);
+    rare_data_ = MakeGarbageCollected<LayoutBlockFlowRareData>(this);
   }
   rare_data_->pagination_strut_propagated_from_child_ = strut;
 }
@@ -4202,7 +4203,7 @@ void LayoutBlockFlow::SetFirstForcedBreakOffset(LayoutUnit block_offset) {
   if (!rare_data_) {
     if (!block_offset)
       return;
-    rare_data_ = std::make_unique<LayoutBlockFlowRareData>(this);
+    rare_data_ = MakeGarbageCollected<LayoutBlockFlowRareData>(this);
   }
   rare_data_->first_forced_break_offset_ = block_offset;
 }
@@ -4317,7 +4318,7 @@ LayoutBlockFlow::LayoutBlockFlowRareData& LayoutBlockFlow::EnsureRareData() {
   if (rare_data_)
     return *rare_data_;
 
-  rare_data_ = std::make_unique<LayoutBlockFlowRareData>(this);
+  rare_data_ = MakeGarbageCollected<LayoutBlockFlowRareData>(this);
   return *rare_data_;
 }
 

third_party/blink/renderer/core/layout/layout_block_flow.h

@@ -733,9 +733,8 @@ class CORE_EXPORT LayoutBlockFlow : public LayoutBlock {
   MarginValues MarginValuesForChild(LayoutBox& child) const;
 
   // Allocated only when some of these fields have non-default values
-  struct LayoutBlockFlowRareData {
-    USING_FAST_MALLOC(LayoutBlockFlowRareData);
-
+  struct LayoutBlockFlowRareData final
+      : public GarbageCollected<LayoutBlockFlowRareData> {
    public:
     explicit LayoutBlockFlowRareData(const LayoutBlockFlow* block);
     ~LayoutBlockFlowRareData();
@@ -755,6 +754,8 @@ class CORE_EXPORT LayoutBlockFlow : public LayoutBlock {
       return (-block->MarginAfter()).ClampNegativeToZero();
     }
 
+    void Trace(Visitor*) {}
+
     MarginValues margins_;
     LayoutUnit pagination_strut_propagated_from_child_;
 
@@ -911,7 +912,7 @@ class CORE_EXPORT LayoutBlockFlow : public LayoutBlock {
   bool CheckIfIsSelfCollapsingBlock() const;
 
  protected:
-  std::unique_ptr<LayoutBlockFlowRareData> rare_data_;
+  Persistent<LayoutBlockFlowRareData> rare_data_;
   std::unique_ptr<FloatingObjects> floating_objects_;
 
   friend class MarginInfo;