Nix GetRootWindowController, use RootWindowController::ForWindow.

ash/system/toast/toast_overlay.cc

 // Copyright 2016 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/system/toast/toast_overlay.h"
 
 #include "ash/public/cpp/ash_typography.h"
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/root_window_controller.h"
 #include "ash/shelf/shelf.h"
@@ skipping 197 matching lines @@
   views::Widget::InitParams params;
   params.type = views::Widget::InitParams::TYPE_POPUP;
   params.name = "ToastOverlay";
   params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
   params.ownership = views::Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
   params.accept_events = true;
   params.keep_on_top = true;
   params.remove_standard_frame = true;
   params.bounds = CalculateOverlayBounds();
   // Show toasts above the app list and below the lock screen.
-  GetRootWindowController(Shell::GetRootWindowForNewWindows())
+  RootWindowController::ForWindow(Shell::GetRootWindowForNewWindows())
       ->ConfigureWidgetInitParamsForContainer(
           overlay_widget_.get(), kShellWindowId_SystemModalContainer, &params);
   overlay_widget_->Init(params);
   overlay_widget_->SetVisibilityChangedAnimationsEnabled(true);
   overlay_widget_->SetContentsView(overlay_view_.get());
   overlay_widget_->SetBounds(CalculateOverlayBounds());
 
   aura::Window* overlay_window = overlay_widget_->GetNativeWindow();
   ::wm::SetWindowVisibilityAnimationType(
       overlay_window, ::wm::WINDOW_VISIBILITY_ANIMATION_TYPE_VERTICAL);
@@ skipping 60 matching lines @@
 ToastOverlayButton* ToastOverlay::dismiss_button_for_testing() {
   return overlay_view_->button();
 }
 
 void ToastOverlay::ClickDismissButtonForTesting(const ui::Event& event) {
   DCHECK(overlay_view_->button());
   overlay_view_->button()->NotifyClick(event);
 }
 
 }  // namespace ash