Make VisibleSelection::AppendTrailingWhitespace() as const function

third_party/WebKit/Source/core/editing/VisibleSelection.cpp

 /*
  * Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 162 matching lines @@
   // beginning of the next text node, each of which has a different style.
   //
   // On a treasure map, <b>X</b> marks the spot.
   //                       ^ selected
   //
   DCHECK(IsRange());
   return NormalizeRange(EphemeralRangeTemplate<Strategy>(start_, end_));
 }
 
 template <typename Strategy>
-void VisibleSelectionTemplate<Strategy>::AppendTrailingWhitespace() {
+VisibleSelectionTemplate<Strategy>
+VisibleSelectionTemplate<Strategy>::AppendTrailingWhitespace() const {
   if (IsNone())
-    return;
+    return *this;
   DCHECK_EQ(granularity_, kWordGranularity);
   if (!IsRange())
-    return;
+    return *this;
   const PositionTemplate<Strategy>& new_end = SkipWhitespace(end_);
   if (end_ == new_end)
-    return;
-  has_trailing_whitespace_ = true;
-  end_ = new_end;
+    return *this;
+  VisibleSelectionTemplate<Strategy> result = *this;
+  result.has_trailing_whitespace_ = true;
+  result.end_ = new_end;
+  return result;
 }
 
 template <typename Strategy>
 void VisibleSelectionTemplate<Strategy>::SetBaseAndExtentToDeepEquivalents() {
   // Move the selection to rendered positions, if possible.
   bool base_and_extent_equal = base_ == extent_;
   if (base_.IsNotNull()) {
     base_ = CreateVisiblePosition(base_, affinity_).DeepEquivalent();
     if (base_and_extent_equal)
       extent_ = base_;
@@ skipping 241 matching lines @@
     // to do this operation, since all selection changes that result in a
     // RANGE come through here before anyone uses it.
     // TODO(yosin) Canonicalizing is good, but haven't we already done it
     // (when we set these two positions to |VisiblePosition|
     // |deepEquivalent()|s above)?
     start_ = MostForwardCaretPosition(start_);
     end_ = MostBackwardCaretPosition(end_);
   }
   if (!has_trailing_whitespace_)
     return;
-  AppendTrailingWhitespace();
+  *this = AppendTrailingWhitespace();
 }
 
 template <typename Strategy>
 bool VisibleSelectionTemplate<Strategy>::IsValidFor(
     const Document& document) const {
   if (IsNone())
     return true;
 
   return base_.GetDocument() == &document && !base_.IsOrphan() &&
          !extent_.IsOrphan() && !start_.IsOrphan() && !end_.IsOrphan();
@@ skipping 310 matching lines @@
 
 void showTree(const blink::VisibleSelectionInFlatTree& sel) {
   sel.ShowTreeForThis();
 }
 
 void showTree(const blink::VisibleSelectionInFlatTree* sel) {
   if (sel)
     sel->ShowTreeForThis();
 }
 #endif