Refactor screen/monitor so that gfx::Screen returns monitor object.

ui/gfx/screen_unittest.cc

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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/gfx/screen.h"
+
 #include "testing/gtest/include/gtest/gtest.h"
-#include "ui/gfx/screen.h"
+#include "ui/gfx/monitor.h"
 
 namespace {
 
 typedef testing::Test ScreenTest;
 
 TEST_F(ScreenTest, GetPrimaryMonitorSize) {
   // We aren't actually testing that it's correct, just that it's sane.
-  const gfx::Size size = gfx::Screen::GetPrimaryMonitorSize();
+  const gfx::Size size = gfx::Screen::GetPrimaryMonitor()->GetSize();
   EXPECT_GE(size.width(), 1);
   EXPECT_GE(size.height(), 1);
 }
 
 TEST_F(ScreenTest, GetNumMonitors) {
   // We aren't actually testing that it's correct, just that it's sane.
   EXPECT_GE(gfx::Screen::GetNumMonitors(), 1);
 }
 
 }  // namespace