Remove some ifdefs from ash since it only supports ChromeOS now.

ash/display/mirror_window_controller.cc

 // Copyright (c) 2013 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/display/mirror_window_controller.h"
 
 #include <utility>
 
-#if defined(USE_X11)
 #include <X11/extensions/XInput2.h>
 #include <X11/Xlib.h>
 
 // Xlib.h defines RootWindow.
 #undef RootWindow
-#endif
 
 #include "ash/display/cursor_window_controller.h"
 #include "ash/display/root_window_transformers.h"
 #include "ash/display/screen_position_controller.h"
 #include "ash/display/window_tree_host_manager.h"
 #include "ash/host/ash_window_tree_host.h"
 #include "ash/host/ash_window_tree_host_init_params.h"
 #include "ash/host/root_window_transformer.h"
 #include "ash/root_window_settings.h"
 #include "ash/shell.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "ui/aura/client/capture_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/aura/window_tree_host.h"
+#include "ui/aura/window_tree_host_x11.h"
 #include "ui/base/layout.h"
 #include "ui/compositor/reflector.h"
 #include "ui/display/display_layout.h"
 #include "ui/display/manager/display_manager.h"
 #include "ui/display/manager/managed_display_info.h"
 #include "ui/display/screen.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/native_widget_types.h"
-
-#if defined(USE_X11)

[Evan Stade, 2017/01/13 17:19:34]

Am I correct in thinking OS_CHROMEOS implies USE_X11? It seems the only linux
config that doesn't use x11 is chromecast.

[James Cook, 2017/01/13 20:19:31]

No, real Chromebooks don't run X. They use our own Ozone code backed directly by
the Linux kernel DRM system. So we still need these ifdefs.

[Evan Stade, 2017/01/19 00:36:21]

ah, ok. restored

-#include "ui/aura/window_tree_host_x11.h"
 #include "ui/gfx/x/x11_types.h"  // nogncheck
-#endif
 
 namespace ash {
 namespace {
 
 // ScreenPositionClient for mirroring windows.
 class MirroringScreenPositionClient
     : public aura::client::ScreenPositionClient {
  public:
   explicit MirroringScreenPositionClient(MirrorWindowController* controller)
       : controller_(controller) {}
@@ skipping 130 matching lines @@
           base::StringPrintf("MirrorRootWindow-%d", mirror_host_count++));
       host->compositor()->SetBackgroundColor(SK_ColorBLACK);
       // No need to remove the observer because the WindowTreeHostManager
       // outlives the host.
       host->AddObserver(Shell::GetInstance()->window_tree_host_manager());
       host->AddObserver(this);
       // TODO(oshima): TouchHUD is using idkey.
       InitRootWindowSettings(host->window())->display_id = display_info.id();
       host->InitHost();
       host->window()->Show();
-#if defined(USE_X11)
       if (!display_manager->IsInUnifiedMode()) {
         // Mirror window shouldn't handle input events.
         static_cast<aura::WindowTreeHostX11*>(host)->DisableInput();
       }
-#endif
 
-#if defined(OS_CHROMEOS)
       if (display_manager->IsInUnifiedMode()) {
         host_info->ash_host->ConfineCursorToRootWindow();
         AshWindowTreeHost* unified_ash_host =
             Shell::GetInstance()
                 ->window_tree_host_manager()
                 ->GetAshWindowTreeHostForDisplayId(
                     display::Screen::GetScreen()->GetPrimaryDisplay().id());
         unified_ash_host->RegisterMirroringHost(host_info->ash_host.get());
         aura::client::SetScreenPositionClient(host->window(),
                                               screen_position_client_.get());
       }
-#endif
 
       aura::client::SetCaptureClient(host->window(), new NoneCaptureClient());
       host->Show();
 
       aura::Window* mirror_window = host_info->mirror_window =
           new aura::Window(nullptr);
       mirror_window->Init(ui::LAYER_SOLID_COLOR);
       host->window()->AddChild(mirror_window);
       host_info->ash_host->SetRootWindowTransformer(std::move(transformer));
       mirror_window->SetBounds(host->window()->bounds());
@@ skipping 148 matching lines @@
   // EventProcessor may be accessed after this call if the mirroring window
   // was deleted as a result of input event (e.g. shortcut), so don't delete
   // now.
   if (delay_host_deletion)
     base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, host_info);
   else
     delete host_info;
 }
 
 }  // namespace ash