Eliminate Shell::RootWindowList in favor of aura::Window::Windows.

ash/wm/system_modal_container_layout_manager_unittest.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 "ash/wm/system_modal_container_layout_manager.h"
 
 #include "ash/root_window_controller.h"
 #include "ash/session_state_delegate.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
@@ skipping 425 matching lines @@
 
 TEST_F(SystemModalContainerLayoutManagerTest, MultiDisplays) {
   if (!SupportsMultipleDisplays())
     return;
 
   UpdateDisplay("500x500,500x500");
 
   scoped_ptr<aura::Window> normal(OpenToplevelTestWindow(false));
   normal->SetBounds(gfx::Rect(100, 100, 50, 50));
 
-  Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
+  aura::Window::Windows root_windows = Shell::GetAllRootWindows();
   EXPECT_EQ(2U, root_windows.size());
   aura::Window* container1 = Shell::GetContainer(
       root_windows[0], ash::internal::kShellWindowId_SystemModalContainer);
   aura::Window* container2 = Shell::GetContainer(
       root_windows[1], ash::internal::kShellWindowId_SystemModalContainer);
 
   scoped_ptr<aura::Window> modal1(
       OpenTestWindowWithParent(container1, true));
   EXPECT_TRUE(AllRootWindowsHaveModalBackgrounds());
   EXPECT_TRUE(wm::IsActiveWindow(modal1.get()));
@@ skipping 29 matching lines @@
 
   // No more modal screen.
   modal1->Hide();
   TestWindow::CloseTestWindow(modal1.release());
   EXPECT_FALSE(AllRootWindowsHaveModalBackgrounds());
   EXPECT_TRUE(wm::IsActiveWindow(normal.get()));
 }
 
 }  // namespace test
 }  // namespace ash