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 181c18076f179045bf1f13b9b2aad9a5ffdb19ab..82e1cc9f052ac89f3f691142e52e977ce181932b 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;