[LayoutNG] Allow block-flow layout to be fragmented using new approach.

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);
 
   // Creates a break token for a node which cannot produce any more fragments.
-  explicit NGBlockBreakToken(NGBlockNode* node);
+  explicit NGBlockBreakToken(NGLayoutInputNode* node);
 
   // TODO(ikilpatrick): Remove this constructor and break_offset once we've

[mstensho (USE GERRIT), 2017/02/27 20:28:20]

Now is the time, I guess?

[ikilpatrick, 2017/02/27 20:44:55]

Done!

   // switched to new multi-col approach.
   NGBlockBreakToken(NGBlockNode* node, LayoutUnit break_offset);
 
   // 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_; }
 
@@ skipping 25 matching lines @@
 
 DEFINE_TYPE_CASTS(NGBlockBreakToken,
                   NGBreakToken,
                   token,
                   token->Type() == NGBreakToken::kBlockBreakToken,
                   token.Type() == NGBreakToken::kBlockBreakToken);
 
 }  // namespace blink
 
 #endif  // NGBlockBreakToken_h