[LayoutNG] Switch NGBreakToken to being RefCounted.

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

 // Copyright 2017 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 NGBlockBreakToken_h
 #define NGBlockBreakToken_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/ng_break_token.h"
 #include "platform/LayoutUnit.h"
 
 namespace blink {
 
 class NGBlockNode;
 
 // Represents a break token for a block node.
 class CORE_EXPORT NGBlockBreakToken : public NGBreakToken {
  public:
   // Creates a break token for a node which did fragment, and can potentially
   // produce more fragments.
   //
   // The NGBlockBreakToken takes ownership of child_break_tokens, leaving it
   // empty for the caller.
-  NGBlockBreakToken(NGBlockNode* node,
-                    LayoutUnit used_block_size,
-                    HeapVector<Member<NGBreakToken>>& child_break_tokens);
+  static RefPtr<NGBlockBreakToken> create(
+      NGBlockNode* node,
+      LayoutUnit used_block_size,
+      Vector<RefPtr<NGBreakToken>>& child_break_tokens) {
+    return adoptRef(
+        new NGBlockBreakToken(node, used_block_size, child_break_tokens));
+  }
 
   // Creates a break token for a node which cannot produce any more fragments.
-  explicit NGBlockBreakToken(NGLayoutInputNode* node);
+  static RefPtr<NGBlockBreakToken> create(NGLayoutInputNode* node) {
+    return adoptRef(new NGBlockBreakToken(node));
+  }
 
   // Represents the amount of block size used in previous fragments.
   //
   // E.g. if the layout block specifies a block size of 200px, and the previous
   // fragments of this block used 150px (used block size), the next fragment
   // should have a size of 50px (assuming no additional fragmentation).
   LayoutUnit UsedBlockSize() const { return used_block_size_; }
 
   // The break tokens for children of the layout node.
   //
   // Each child we have visited previously in the block-flow layout algorithm
   // has an associated break token. This may be either finished (we should skip
   // this child) or unfinished (we should try and produce the next fragment for
   // this child).
   //
   // A child which we haven't visited yet doesn't have a break token here.
-  const HeapVector<Member<NGBreakToken>>& ChildBreakTokens() const {
+  const Vector<RefPtr<NGBreakToken>>& ChildBreakTokens() const {
     return child_break_tokens_;
   }
 
-  DEFINE_INLINE_VIRTUAL_TRACE() {
-    NGBreakToken::trace(visitor);
-    visitor->trace(child_break_tokens_);
-  }
+ private:
+  NGBlockBreakToken(NGBlockNode* node,
+                    LayoutUnit used_block_size,
+                    Vector<RefPtr<NGBreakToken>>& child_break_tokens);
 
- private:
+  explicit NGBlockBreakToken(NGLayoutInputNode* node);
+
   LayoutUnit used_block_size_;
-  HeapVector<Member<NGBreakToken>> child_break_tokens_;
+  Vector<RefPtr<NGBreakToken>> child_break_tokens_;
 };
 
 DEFINE_TYPE_CASTS(NGBlockBreakToken,
                   NGBreakToken,
                   token,
                   token->Type() == NGBreakToken::kBlockBreakToken,
                   token.Type() == NGBreakToken::kBlockBreakToken);
 
 }  // namespace blink
 
 #endif  // NGBlockBreakToken_h