Uses |AXPosition| to enable navigation by character, word and line in content editables on the Mac.

ui/accessibility/ax_node_position_unittest.cc

 // 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.
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 1882 matching lines @@
                    "TextPosition tree_id=0 anchor_id=3 text_offset=9 "
                    "affinity=downstream annotated_text=Check box<>",
                    "NullPosition"}}));
 
 //
 // Tests for |AXRange|.
 //
 
 // TODO(nektar): Move these tests to their own file.
 
-TEST_F(AXPositionTest, AXRangeGetText) {
+TEST_F(AXPositionTest, AXRangeGetTextWithWholeObjects) {
   base::string16 all_text = base::UTF8ToUTF16("ButtonCheck boxLine 1\nLine 2");
   // Create a range starting from the button object and ending at the last
   // character of the root, i.e. at the last character of the second line in the
   // text field.
   TestPositionType start = AXNodePosition::CreateTreePosition(
       tree_.data().tree_id, root_.id, 0 /* child_index */);
   TestPositionType end = AXNodePosition::CreateTextPosition(
       tree_.data().tree_id, root_.id, 28 /* text_offset */,
       AX_TEXT_AFFINITY_DOWNSTREAM);
   AXRange<AXPosition<AXNodePosition, AXNode>> forward_range(start->Clone(),
                                                             end->Clone());
   EXPECT_EQ(all_text, forward_range.GetText());
   AXRange<AXPosition<AXNodePosition, AXNode>> backward_range(std::move(end),
                                                              std::move(start));
   EXPECT_EQ(all_text, backward_range.GetText());
 }
 
+TEST_F(AXPositionTest, AXRangeGetTextWithTextOffsets) {
+  base::string16 most_text = base::UTF8ToUTF16("tonCheck boxLine 1\nLine");
+  // Create a range starting from the third character in the button object and
+  // ending two characters before the end of the root.
+  TestPositionType start = AXNodePosition::CreateTextPosition(
+      tree_.data().tree_id, button_.id, 3 /* text_offset */,
+      AX_TEXT_AFFINITY_DOWNSTREAM);
+  TestPositionType end = AXNodePosition::CreateTextPosition(
+      tree_.data().tree_id, static_text2_.id, 4 /* text_offset */,
+      AX_TEXT_AFFINITY_DOWNSTREAM);
+  AXRange<AXPosition<AXNodePosition, AXNode>> forward_range(start->Clone(),
+                                                            end->Clone());
+  EXPECT_EQ(most_text, forward_range.GetText());
+  AXRange<AXPosition<AXNodePosition, AXNode>> backward_range(std::move(end),
+                                                             std::move(start));
+  EXPECT_EQ(most_text, backward_range.GetText());
+}
+
 }  // namespace ui