Add unittests for X11TopmostWindowFinder

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.cc

 // Copyright (c) 2012 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_x11.h"
 
 #include <X11/extensions/shape.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/Xatom.h>
 #include <X11/Xregion.h>
@@ skipping 1195 matching lines @@
              &xclient);
 }
 
 bool DesktopWindowTreeHostX11::HasWMSpecProperty(const char* property) const {
   return window_properties_.find(atom_cache_.GetAtom(property)) !=
       window_properties_.end();
 }
 
 void DesktopWindowTreeHostX11::SetUseNativeFrame(bool use_native_frame) {
   use_native_frame_ = use_native_frame;
-  x11_window_event_filter_->SetUseHostWindowBorders(use_native_frame);
+  ui::SetUseOSWindowFrame(xwindow_, use_native_frame);
 }
 
 void DesktopWindowTreeHostX11::OnCaptureReleased() {
   x11_capture_.reset();
   g_current_capture = NULL;
   OnHostLostWindowCapture();
   native_widget_delegate_->OnMouseCaptureLost();
 }
 
 void DesktopWindowTreeHostX11::DispatchMouseEvent(ui::MouseEvent* event) {
@@ skipping 484 matching lines @@
   if (linux_ui) {
     ui::NativeTheme* native_theme = linux_ui->GetNativeTheme(window);
     if (native_theme)
       return native_theme;
   }
 
   return ui::NativeTheme::instance();
 }
 
 }  // namespace views