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

third_party/WebKit/Source/core/layout/ng/inline/ng_inline_items_builder.h

 // Copyright 2016 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 NGInlineItemsBuilder_h
 #define NGInlineItemsBuilder_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/inline/ng_inline_node.h"
 #include "platform/wtf/Allocator.h"
@@ skipping 74 matching lines @@
     UChar character;
   } OnExitNode;
   Vector<OnExitNode> exits_;
 
   enum class CollapsibleSpace { kNone, kSpace, kNewline };
 
   CollapsibleSpace last_collapsible_space_ = CollapsibleSpace::kSpace;
   bool is_svgtext_ = false;
   bool has_bidi_controls_ = false;
 
+  void AppendWithWhiteSpaceCollapsing(const String&,
+                                      unsigned start,
+                                      unsigned end,
+                                      const ComputedStyle*,
+                                      LayoutObject*);
+  void AppendWithoutWhiteSpaceCollapsing(const String&,
+                                         const ComputedStyle*,
+                                         LayoutObject*);
+  void AppendWithPreservingNewlines(const String&,
+                                    const ComputedStyle*,
+                                    LayoutObject*);
+
+  void AppendForcedBreak(const ComputedStyle*, LayoutObject*);
+
   // Because newlines may be removed depends on following characters, newlines
   // at the end of input string is not added to |text_| but instead
   // |has_pending_newline_| flag is set.
   // This function determines whether to add the newline or ignore.
   void ProcessPendingNewline(const String&, const ComputedStyle*);
 
   // Removes the collapsible space at the end of |text_| if exists.
   void RemoveTrailingCollapsibleSpaceIfExists(unsigned*);
   void RemoveTrailingCollapsibleSpace(unsigned*);
 
   void RemoveTrailingCollapsibleNewlineIfNeeded(unsigned*,
                                                 const String&,
                                                 unsigned,
                                                 const ComputedStyle*);
 
   void Enter(LayoutObject*, UChar);
   void Exit(LayoutObject*);
 };
 
 }  // namespace blink
 
 #endif  // NGInlineItemsBuilder_h