Allow dynamic enabling/disabling of unified desktop

ash/screen_util_unittest.cc

 // Copyright 2014 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/screen_util.h"
 
 #include "ash/display/display_manager.h"
 #include "ash/root_window_controller.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shelf/shelf_widget.h"
@@ skipping 99 matching lines @@
           primary->GetNativeView(), gfx::Rect(30, 30, 100, 100)).ToString());
   EXPECT_EQ(
       "650,50 100x100",
       ScreenUtil::ConvertRectToScreen(
           secondary->GetNativeView(), gfx::Rect(40, 40, 100, 100)).ToString());
 }
 
 TEST_F(ScreenUtilTest, ShelfDisplayBoundsInUnifiedDesktop) {
   if (!SupportsMultipleDisplays())
     return;
-  test::DisplayManagerTestApi::EnableUnifiedDesktopForTest();
+  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
 
-  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
-  display_manager->SetDefaultMultiDisplayMode(DisplayManager::UNIFIED);
-  display_manager->SetMultiDisplayMode(DisplayManager::UNIFIED);
+  display_manager->SetUnifiedDesktopEnabled(true);
 
   views::Widget* widget = views::Widget::CreateWindowWithContextAndBounds(
       NULL, CurrentContext(), gfx::Rect(10, 10, 100, 100));
 
   UpdateDisplay("500x400");
   EXPECT_EQ("0,0 500x400", ScreenUtil::GetShelfDisplayBoundsInScreen(
                                widget->GetNativeWindow()).ToString());
 
   UpdateDisplay("500x400,600x400");
   EXPECT_EQ("0,0 500x400", ScreenUtil::GetShelfDisplayBoundsInScreen(
                                widget->GetNativeWindow()).ToString());
 
   // Move to the 2nd physical display. Shelf's display still should be
   // the first.
   widget->SetBounds(gfx::Rect(800, 0, 100, 100));
   ASSERT_EQ("800,0 100x100", widget->GetWindowBoundsInScreen().ToString());
 
   EXPECT_EQ("0,0 500x400", ScreenUtil::GetShelfDisplayBoundsInScreen(
                                widget->GetNativeWindow()).ToString());
 
   UpdateDisplay("600x500");
   EXPECT_EQ("0,0 600x500", ScreenUtil::GetShelfDisplayBoundsInScreen(
                                widget->GetNativeWindow()).ToString());
 }
 
 }  // namespace test
 }  // namespace ash