ozone/platform/wayland: Drop WaylandWindow::GetWidget()

ui/ozone/platform/wayland/wayland_test.cc

 // 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/ozone/platform/wayland/wayland_test.h"
 
+using ::testing::SaveArg;
+using ::testing::_;
+
 namespace ui {
 
 WaylandTest::WaylandTest()
     : window(&delegate, &display, gfx::Rect(0, 0, 800, 600)) {}
 
 WaylandTest::~WaylandTest() {}
 
 void WaylandTest::SetUp() {
   ASSERT_TRUE(server.Start());
   ASSERT_TRUE(display.Initialize());
+  EXPECT_CALL(delegate, OnAcceleratedWidgetAvailable(_, _))
+      .WillOnce(SaveArg<0>(&widget));
   ASSERT_TRUE(window.Initialize());
+  ASSERT_NE(widget, gfx::kNullAcceleratedWidget);
   wl_display_roundtrip(display.display());
 
   server.Pause();
 
-  surface = server.GetObject<wl::MockSurface>(window.GetWidget());
+  surface = server.GetObject<wl::MockSurface>(widget);
   ASSERT_TRUE(surface);
   initialized = true;
 }
 
 void WaylandTest::TearDown() {
   server.Resume();
   if (initialized)
     wl_display_roundtrip(display.display());
 }
 
 void WaylandTest::Sync() {
   server.Resume();
   wl_display_roundtrip(display.display());
   server.Pause();
 }
 
 }  // namespace ui