RenderTextHarfBuzz: Add support for multi line text selection.

ui/views/style/platform_style.h

 // Copyright 2015 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_VIEWS_STYLE_PLATFORM_STYLE_H_
 #define UI_VIEWS_STYLE_PLATFORM_STYLE_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 22 matching lines @@
   // Minimum size for platform-styled buttons (Button::STYLE_BUTTON).
   static const int kMinLabelButtonWidth;
   static const int kMinLabelButtonHeight;
 
   // Whether dialog-default buttons are given a bold font style.
   static const bool kDefaultLabelButtonHasBoldFont;
 
   // Whether the default button for a dialog can be the Cancel button.
   static const bool kDialogDefaultButtonCanBeCancel;
 
-  // Whether dragging vertically above or below a text view's bounds selects to
-  // the left or right end of the text from the cursor, respectively.
-  static const bool kTextDragVerticallyDragsToEnd;
-
   // The menu button's action to show the menu.
   static const CustomButton::NotifyAction kMenuNotifyActivationAction;
 
   // Whether TreeViews get a focus ring on the entire TreeView when focused.
   static const bool kTreeViewHasFocusRing;
 
   // Whether selecting a row in a TreeView selects the entire row or only the
   // label for that row.
   static const bool kTreeViewSelectionPaintsEntireRow;
 
@@ skipping 32 matching lines @@
   // the failed edit if platform-appropriate.
   static void OnTextfieldEditFailed();
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PlatformStyle);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_STYLE_PLATFORM_STYLE_H_