[LayoutNG] Add "Control" NGInlineItemType for newlines and tabs

third_party/WebKit/Source/core/layout/ng/inline/ng_inline_item.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 NGInlineItem_h
 #define NGInlineItem_h
 
 #include "platform/LayoutUnit.h"
 #include "platform/fonts/FontFallbackPriority.h"
 #include "platform/fonts/SimpleFontData.h"
@@ skipping 10 matching lines @@
 
 // Class representing a single text node or styled inline element with text
 // content segmented by style, text direction, sideways rotation, font fallback
 // priority (text, symbol, emoji, etc), and script (but not by font).
 // In this representation TextNodes are merged up into their parent inline
 // element where possible.
 class NGInlineItem {
  public:
   enum NGInlineItemType {
     kText,
+    kControl,
     kAtomicInline,
     kOpenTag,
     kCloseTag,
     kFloating,
     kOutOfFlowPositioned,
     kBidiControl
     // When adding new values, make sure the bit size of |type_| is large
     // enough to store.
   };
 
@@ skipping 124 matching lines @@
 
  private:
   NGInlineItem* start_item_;
   unsigned size_;
   unsigned start_index_;
 };
 
 }  // namespace blink
 
 #endif  // NGInlineItem_h