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

ash/drag_drop/drag_drop_controller_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/drag_drop/drag_drop_controller.h"
 
 #include "ash/drag_drop/drag_drop_tracker.h"
 #include "ash/drag_drop/drag_image_view.h"
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
@@ skipping 1002 matching lines @@
 
 }
 
 // Verifies the drag image moves back to the position where drag is started
 // across displays when drag is cancelled.
 TEST_F(DragDropControllerTest, DragCancelAcrossDisplays) {
   if (!SupportsMultipleDisplays())
     return;
 
   UpdateDisplay("400x400,400x400");
-  Shell::RootWindowList root_windows =
+  aura::Window::Windows root_windows =
       Shell::GetInstance()->GetAllRootWindows();
-  for (Shell::RootWindowList::iterator iter = root_windows.begin();
+  for (aura::Window::Windows::iterator iter = root_windows.begin();
        iter != root_windows.end(); ++iter) {
     aura::client::SetDragDropClient(*iter, drag_drop_controller_.get());
   }
 
   ui::OSExchangeData data;
   data.SetString(UTF8ToUTF16("I am being dragged"));
   {
     scoped_ptr<views::Widget> widget(CreateNewWidget());
     aura::Window* window = widget->GetNativeWindow();
     drag_drop_controller_->StartDragAndDrop(
@@ skipping 56 matching lines @@
                        gfx::Point(200, 0),
                        ui::EF_NONE);
       drag_drop_controller_->DragUpdate(window, e);
     }
 
     drag_drop_controller_->DragCancel();
     CompleteCancelAnimation();
 
     EXPECT_EQ("405,405", observer.window_location_on_destroying().ToString());
   }
-  for (Shell::RootWindowList::iterator iter = root_windows.begin();
+  for (aura::Window::Windows::iterator iter = root_windows.begin();
        iter != root_windows.end(); ++iter) {
     aura::client::SetDragDropClient(*iter, NULL);
   }
 }
 
 }  // namespace test
 }  // namespace aura