RenderTextHarfBuzz: Add support for multi line text selection.

ui/views/style/platform_style_mac.mm

 // 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.
 
 #include "ui/views/style/platform_style.h"
 
 #include "base/memory/ptr_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_features.h"
 #include "ui/gfx/color_utils.h"
 #include "ui/gfx/paint_vector_icon.h"
 #include "ui/gfx/vector_icons_public.h"
 #include "ui/resources/grit/ui_resources.h"
 #include "ui/views/controls/button/label_button.h"
 #import "ui/views/controls/scrollbar/cocoa_scroll_bar.h"
 
 #import <Cocoa/Cocoa.h>
 
 namespace views {
 
 const int PlatformStyle::kComboboxNormalArrowPadding = 0;
 const int PlatformStyle::kMinLabelButtonWidth = 32;
 const int PlatformStyle::kMinLabelButtonHeight = 30;
 const bool PlatformStyle::kDefaultLabelButtonHasBoldFont = false;
 const bool PlatformStyle::kDialogDefaultButtonCanBeCancel = false;
-const bool PlatformStyle::kTextDragVerticallyDragsToEnd = true;
 const bool PlatformStyle::kTreeViewHasFocusRing = true;
 const bool PlatformStyle::kTreeViewSelectionPaintsEntireRow = true;
 const bool PlatformStyle::kUseRipples = false;
 
 // On Mac, the Cocoa browser window does not flip its UI in RTL (e.g. bookmark
 // star remains on the right, padlock on the left). So bubbles should open in
 // the same direction as in LTR by default, unless the entire browser is views.
 const bool PlatformStyle::kMirrorBubbleArrowInRTLByDefault =
     BUILDFLAG(MAC_VIEWS_BROWSER);
 
@@ skipping 41 matching lines @@
   ButtonColorByState& colors = *color_by_state;
   colors[Button::STATE_PRESSED] = SK_ColorWHITE;
 }
 
 // static
 void PlatformStyle::OnTextfieldEditFailed() {
   NSBeep();
 }
 
 }  // namespace views