The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/81217a22a1dc79485433f211e35eaca71167a369

commit 81217a22a1dc79485433f211e35eaca71167a369
Author: estade <estade@chromium.org>
Date: Wed Feb 15 22:48:16 2017

Reuse submenu arrow images for trees (like the edit bookmark tree).

This makes our UI more consistent and makes the arrows look
significantly better at 1.25x scale.

BUG= 692270 

Review-Url: https://codereview.chromium.org/2694323003
Cr-Commit-Position: refs/heads/master@{#450822}

[modify] https://crrev.com/81217a22a1dc79485433f211e35eaca71167a369/chrome/browser/ui/libgtkui/native_theme_gtk2.cc
[modify] https://crrev.com/81217a22a1dc79485433f211e35eaca71167a369/chrome/browser/ui/libgtkui/native_theme_gtk3.cc
[modify] https://crrev.com/81217a22a1dc79485433f211e35eaca71167a369/ui/native_theme/common_theme.cc
[modify] https://crrev.com/81217a22a1dc79485433f211e35eaca71167a369/ui/native_theme/native_theme.h
[modify] https://crrev.com/81217a22a1dc79485433f211e35eaca71167a369/ui/native_theme/native_theme_dark_aura.cc
[modify] https://crrev.com/81217a22a1dc79485433f211e35eaca71167a369/ui/native_theme/native_theme_mac.mm
[modify] https://crrev.com/81217a22a1dc79485433f211e35eaca71167a369/ui/native_theme/native_theme_win.cc
[modify] https://crrev.com/81217a22a1dc79485433f211e35eaca71167a369/ui/views/controls/tree/tree_view.cc