Adds support for multiple displays to WmTestBase

ash/mus/test/wm_test_screen.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 "ash/mus/test/wm_test_screen.h"
-
-#include "ui/aura/window.h"
-#include "ui/display/display_finder.h"
-
-namespace ash {
-namespace mus {
-
-WmTestScreen::WmTestScreen() {}
-WmTestScreen::~WmTestScreen() {}
-
-gfx::Point WmTestScreen::GetCursorScreenPoint() {
-  // TODO(sky): use the implementation from WindowManagerConnection.
-  DVLOG(1) << "NOTIMPLEMENTED";
-  return gfx::Point();
-}
-
-bool WmTestScreen::IsWindowUnderCursor(gfx::NativeWindow window) {
-  if (!window)
-    return false;
-
-  return window->IsVisible() &&
-         window->GetBoundsInScreen().Contains(GetCursorScreenPoint());
-}
-
-}  // namespace mus
-}  // namespace ash