views: support vertical-drag-to-end on textfields

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 "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/views/controls/button/button.h"
 
 namespace views {
 
 class Border;
 class LabelButton;
 class LabelButtonBorder;
 
 // Cross-platform API for providing platform-specific styling for toolkit-views.
 class PlatformStyle {
  public:
+  // True if dragging vertically above or below a textfield's bounds selects to
+  // the beginning or end of the text from the cursor, respectively.
+  VIEWS_EXPORT static const bool kTextfieldDragVerticallyDragsToEnd;

[tapted, 2016/04/15 00:35:08]

#include ui/views/views_export.h for this. Also I think we should just
VIEWS_EXPORT the entire class - pretty sure the static member will inherit that
(and there's not point being stingy with exports since it #defines to the empty
string in release builds)

[Elly Fong-Jones, 2016/04/15 14:47:46]

After a rebase, it seems like it is already included, and the entire class is
already VIEWS_EXPORTed?

[tapted, 2016/04/18 01:14:39]

ahyep - that was me :3

+
   // Creates the default label button border for the given |style|. Used when a
   // custom default border is not provided for a particular LabelButton class.
   static scoped_ptr<LabelButtonBorder> CreateLabelButtonBorder(
       Button::ButtonStyle style);
 
   // Applies the current system theme to the default border created by |button|.
   static scoped_ptr<Border> CreateThemedLabelButtonBorder(LabelButton* button);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PlatformStyle);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_STYLE_PLATFORM_STYLE_H_