views: remove dead code

Now that DesktopNativeWidgetAura is not compiled on chromeos, this code
is unnecessary.

BUG=958241
TEST=none

Change-Id: I5903f1a2b3b53d95f75525eb9b8cdf555215189f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1627651
Reviewed-by: Evan Stade <estade@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662689}
diff --git a/ui/views/BUILD.gn b/ui/views/BUILD.gn
index c73caf1e..5402768 100644
--- a/ui/views/BUILD.gn
+++ b/ui/views/BUILD.gn
@@ -562,7 +562,6 @@
       "controls/menu/menu_config_linux.cc",
       "linux_ui/status_icon_linux.cc",
     ]
-    sources += [ "widget/desktop_aura/desktop_window_tree_host_chromeos.cc" ]
   }
 
   if (is_win) {
diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_chromeos.cc b/ui/views/widget/desktop_aura/desktop_window_tree_host_chromeos.cc
deleted file mode 100644
index d0caf5e..0000000
--- a/ui/views/widget/desktop_aura/desktop_window_tree_host_chromeos.cc
+++ /dev/null
@@ -1,20 +0,0 @@
-// Copyright 2016 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/widget/desktop_aura/desktop_window_tree_host.h"
-
-namespace views {
-
-// static
-DesktopWindowTreeHost* DesktopWindowTreeHost::Create(
-    internal::NativeWidgetDelegate* native_widget_delegate,
-    DesktopNativeWidgetAura* desktop_native_widget_aura) {
-  // DesktopNativeWidgetAura is only used with mus, and MusClient sets itself
-  // as the factory for both NativeWidgets and DesktopWindowTreeHosts, so this
-  // should never be called.
-  NOTREACHED();
-  return nullptr;
-}
-
-}  // namespace views