Make GetRootWindow() return a Window instead of a RootWindow.

ash/wm/drag_window_resizer.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/drag_window_resizer.h"
 
 #include "ash/display/mouse_cursor_event_filter.h"
 #include "ash/root_window_controller.h"
 #include "ash/screen_ash.h"
 #include "ash/shell.h"
@@ skipping 20 matching lines @@
 // The maximum opacity of the drag phantom window.
 const float kMaxOpacity = 0.8f;
 
 // Returns true if Ash has more than one root window.
 bool HasSecondaryRootWindow() {
   return Shell::GetAllRootWindows().size() > 1;
 }
 
 // When there are two root windows, returns one of the root windows which is not
 // |root_window|. Returns NULL if only one root window exists.
-aura::RootWindow* GetAnotherRootWindow(aura::RootWindow* root_window) {
+aura::RootWindow* GetAnotherRootWindow(aura::Window* root_window) {
   Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
   if (root_windows.size() < 2)
     return NULL;
   DCHECK_EQ(2U, root_windows.size());
   if (root_windows[0] == root_window)
     return root_windows[1];
   return root_windows[0];
 }
 
 }  // namespace
@@ skipping 112 matching lines @@
   }
   instance_ = this;
 }
 
 void DragWindowResizer::UpdateDragWindow(const gfx::Rect& bounds,
                                          bool in_original_root) {
   if (details_.window_component != HTCAPTION || !ShouldAllowMouseWarp())
     return;
 
   // It's available. Show a phantom window on the display if needed.
-  aura::RootWindow* another_root =
+  aura::Window* another_root =
       GetAnotherRootWindow(GetTarget()->GetRootWindow());
   const gfx::Rect root_bounds_in_screen(another_root->GetBoundsInScreen());
   const gfx::Rect bounds_in_screen =
       ScreenAsh::ConvertRectToScreen(GetTarget()->parent(), bounds);
   gfx::Rect bounds_in_another_root =
       gfx::IntersectRects(root_bounds_in_screen, bounds_in_screen);
   const float fraction_in_another_window =
       (bounds_in_another_root.width() * bounds_in_another_root.height()) /
       static_cast<float>(bounds.width() * bounds.height());
 
@@ skipping 78 matching lines @@
   if (!tray_user->TransferWindowToUser(details_.window)) {
     GetTarget()->layer()->SetOpacity(old_opacity);
     return false;
   }
   RevertDrag();
   return true;
 }
 
 }  // namespace internal
 }  // namespace ash