Nix GetRootWindowController, use RootWindowController::ForWindow.

ash/screen_util.cc

Index: ash/screen_util.cc
diff --git a/ash/screen_util.cc b/ash/screen_util.cc
index b6cbf6030566908ba23500c33c9a58e55f042ab4..072ca79a976c25bc3f1bea4b805527391a4c78c5 100644
--- a/ash/screen_util.cc
+++ b/ash/screen_util.cc
@@ -4,7 +4,6 @@
 
 #include "ash/screen_util.h"
 
-#include "ash/root_window_controller.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shell.h"
 #include "ash/shell_port.h"
@@ -21,8 +20,7 @@ namespace ash {
 
 // static
 gfx::Rect ScreenUtil::GetMaximizedWindowBoundsInParent(aura::Window* window) {
-  aura::Window* root_window = window->GetRootWindow();
-  if (GetRootWindowController(root_window)->shelf()->shelf_widget())
+  if (Shelf::ForWindow(window)->shelf_widget())
     return GetDisplayWorkAreaBoundsInParent(window);
   return GetDisplayBoundsInParent(window);
 }