RenderTextHarfBuzz: Add support for multi line text selection.

ui/views/style/platform_style.h

Index: ui/views/style/platform_style.h
diff --git a/ui/views/style/platform_style.h b/ui/views/style/platform_style.h
index 67c7ae0fcd69d7c8ccdc6c812f199d99e9d94f9f..590afb92bed1aa516b14522c9224de925234bfb4 100644
--- a/ui/views/style/platform_style.h
+++ b/ui/views/style/platform_style.h
@@ -40,10 +40,6 @@ class VIEWS_EXPORT PlatformStyle {
   // 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;