MacViews: Fix behavior of move and select commands when selection direction changes.

ui/gfx/render_text.h

 // Copyright (c) 2012 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 UI_GFX_RENDER_TEXT_H_
 #define UI_GFX_RENDER_TEXT_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 311 matching lines @@
   const SelectionModel& selection_model() const { return selection_model_; }
 
   const Range& selection() const { return selection_model_.selection(); }
 
   size_t cursor_position() const { return selection_model_.caret_pos(); }
   void SetCursorPosition(size_t position);
 
   // Moves the cursor left or right. Cursor movement is visual, meaning that
   // left and right are relative to screen, not the directionality of the text.
   // If |select| is false, the selection start is moved to the same position.
-  void MoveCursor(BreakType break_type,
-                  VisualCursorDirection direction,
-                  bool select);
+  // |select_behavior| specifies the selection behavior in case the selection
+  // direction is reversed.
+  void MoveCursor(
+      BreakType break_type,
+      VisualCursorDirection direction,
+      bool select,
+      SelectionReversedBehavior select_behavior = SELECTION_DEFAULT);

[tapted, 2016/08/11 03:44:07]

This isn't a good use of default arguments - if |select| is true we want the
caller to think about how it should behave - see later comment.

[karandeepb, 2016/08/16 10:24:51]

Acknowledged, removed the use of default args.

 
   // Set the selection_model_ to the value of |selection|.
   // The selection range is clamped to text().length() if out of range.
   // Returns true if the cursor position or selection range changed.
   // If any index in |selection_model| is not a cursorable position (not on a
   // grapheme boundary), it is a no-op and returns false.
   bool MoveCursorTo(const SelectionModel& selection_model);
 
   // Set the selection_model_ based on |range|.
   // If the |range| start or end is greater than text length, it is modified
@@ skipping 504 matching lines @@
   // Lines computed by EnsureLayout. These should be invalidated upon
   // OnLayoutTextAttributeChanged and OnDisplayTextAttributeChanged calls.
   std::vector<internal::Line> lines_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderText);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_RENDER_TEXT_H_