exo: Confine windows to primary display

components/exo/wm_helper_ash.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 "components/exo/wm_helper_ash.h"
 
 #include "ash/accessibility_delegate.h"
 #include "ash/public/cpp/config.h"
 #include "ash/shell.h"
 #include "ash/shell_port.h"
@@ skipping 42 matching lines @@
 
 ////////////////////////////////////////////////////////////////////////////////
 // WMHelperAsh, private:
 
 const display::ManagedDisplayInfo WMHelperAsh::GetDisplayInfo(
     int64_t display_id) const {
   return ash::Shell::Get()->display_manager()->GetDisplayInfo(display_id);
 }
 
 aura::Window* WMHelperAsh::GetContainer(int container_id) {
-  return ash::Shell::GetContainer(ash::Shell::GetRootWindowForNewWindows(),
+  // TODO(domlaskowski): Use target root window once multi-display support lands
+  // in ARC. See crbug.com/718627.
+  return ash::Shell::GetContainer(ash::Shell::GetPrimaryRootWindow(),
                                   container_id);
 }
 
 aura::Window* WMHelperAsh::GetActiveWindow() const {
   return ash::Shell::Get()->activation_client()->GetActiveWindow();
 }
 
 aura::Window* WMHelperAsh::GetFocusedWindow() const {
   aura::client::FocusClient* focus_client =
       aura::client::GetFocusClient(ash::Shell::GetPrimaryRootWindow());
@@ skipping 80 matching lines @@
 
 void WMHelperAsh::OnDisplayConfigurationChanged() {
   NotifyDisplayConfigurationChanged();
 }
 
 void WMHelperAsh::OnKeyboardDeviceConfigurationChanged() {
   NotifyKeyboardDeviceConfigurationChanged();
 }
 
 }  // namespace exo