Make VisibleSelection::AppendTrailingWhitespace() as const function

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

 // Copyright 2014 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.
 
 #include "core/editing/VisibleSelection.h"
 
 #include "core/dom/Range.h"
 #include "core/editing/EditingTestBase.h"
 #include "core/editing/SelectionAdjuster.h"
 
@@ skipping 64 matching lines @@
 TEST_F(VisibleSelectionTest, appendTrailingWhitespaceWithAfterAnchor) {
   SetBodyContent(
       "<input type=checkbox>"
       "<div style='user-select:none'>abc</div>");
   Element* const input = GetDocument().QuerySelector("input");
 
   // Simulate double-clicking "abc".
   // TODO(editing-dev): We should remove above comment once we fix [1].
   // [1] http://crbug.com/701657 double-click on user-select:none should not
   // compute selection.
-  VisibleSelection selection =
+  const VisibleSelection selection =
       CreateVisibleSelection(SelectionInDOMTree::Builder()
                                  .Collapse(Position::BeforeNode(*input))
                                  .Extend(Position::AfterNode(*input))
                                  .SetGranularity(kWordGranularity)
                                  .Build());
-  selection.AppendTrailingWhitespace();
+  const VisibleSelection result = selection.AppendTrailingWhitespace();
 
-  EXPECT_EQ(Position::BeforeNode(*input), selection.Start());
-  EXPECT_EQ(Position::AfterNode(*input), selection.End());
+  EXPECT_EQ(Position::BeforeNode(*input), result.Start());
+  EXPECT_EQ(Position::AfterNode(*input), result.End());
 }
 
 TEST_F(VisibleSelectionTest, expandUsingGranularity) {
   const char* body_content =
       "<span id=host><a id=one>1</a><a id=two>22</a></span>";
   const char* shadow_content =
       "<p><b id=three>333</b><content select=#two></content><b "
       "id=four>4444</b><span id=space>  </span><content "
       "select=#one></content><b id=five>55555</b></p>";
   SetBodyContent(body_content);
@@ skipping 427 matching lines @@
   Element* host = GetDocument().getElementById("host");
   host->AppendChild(sample);
   GetDocument().UpdateStyleAndLayout();
 
   // Simulates to restore selection from undo stack.
   selection = CreateVisibleSelection(selection.AsSelection());
   EXPECT_EQ(Position(sample->firstChild(), 0), selection.Start());
 }
 
 }  // namespace blink