Move SetUseOverrideRedirectWindowByDefault() to //ui/base.

ui/base/platform_window_defaults.h

+// Copyright 2017 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_BASE_PLATFORM_WINDOW_DEFAULTS_H_
+#define UI_BASE_PLATFORM_WINDOW_DEFAULTS_H_
+
+#include "ui/base/ui_base_export.h"
+
+namespace ui {
+
+// Gets the |override_redirect| flag used when creating an X11 window.
+UI_BASE_EXPORT bool GetUseOverrideRedirectWindowByDefault();
+
+namespace test {
+
+// Sets the value of the |override_redirect| flag when creating an X11 window.
+// It is necessary to set this flag on for various tests, otherwise the call to
+// Show() blocks because it never receives the MapNotify event. It is unclear
+// why this is necessary, but might be related to calls to XInitThreads().
+//
+// This can be called safely on all platforms. For non-X11 platforms it will
+// have no effect.
+UI_BASE_EXPORT void SetUseOverrideRedirectWindowByDefault(

[sadrul, 2017/02/09 21:49:35]

Maybe call this something different? like EnableTestConfiguration() or something
like that. It probably doesn't need to take an input param?

[kylechar, 2017/02/10 15:31:03]

Done.

+    bool override_redirect);
+
+}  // namespace test
+}  // namespace ui
+
+#endif  // UI_BASE_PLATFORM_WINDOW_DEFAULTS_H_