Move LayoutDeprecatedFlexibleBox-specific line handling.

third_party/WebKit/Source/core/layout/LayoutBlockFlow.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003-2013 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
@@ skipping 118 matching lines @@
     using LayoutBlock::firstLineBox;
     using LayoutBlock::lastLineBox;
     using LayoutBlock::firstRootBox;
     using LayoutBlock::lastRootBox;
 
     LayoutUnit logicalLeftSelectionOffset(const LayoutBlock* rootBlock, LayoutUnit position) const override;
     LayoutUnit logicalRightSelectionOffset(const LayoutBlock* rootBlock, LayoutUnit position) const override;
 
     RootInlineBox* createAndAppendRootInlineBox();
 
+    // Return the number of lines in *this* block flow. Does not recurse into block flow children.
+    // Will start counting from the first line, and stop counting right after |stopRootInlineBox|,
+    // if specified.
+    int lineCount(const RootInlineBox* stopRootInlineBox = nullptr) const;
+
     void removeFloatingObjectsFromDescendants();
     void markAllDescendantsWithFloatsForLayout(LayoutBox* floatToRemove = nullptr, bool inLayout = true);
     void markSiblingsWithFloatsForLayout(LayoutBox* floatToRemove = nullptr);
 
     bool containsFloats() const { return m_floatingObjects && !m_floatingObjects->set().isEmpty(); }
     bool containsFloat(LayoutBox*) const;
 
     void removeFloatingObjects();
 
     void addChild(LayoutObject* newChild, LayoutObject* beforeChild = nullptr) override;
@@ skipping 458 matching lines @@
 
 // END METHODS DEFINED IN LayoutBlockFlowLine
 
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutBlockFlow, isLayoutBlockFlow());
 
 } // namespace blink
 
 #endif // LayoutBlockFlow_h