Add an adapter layer (WMHelper) between exo and ash.

components/exo/gamepad.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/gamepad.h"
 
 #include <cmath>
 
-#include "ash/shell.h"
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/exo/gamepad_delegate.h"
 #include "components/exo/shell_surface.h"
 #include "components/exo/surface.h"
 #include "device/gamepad/gamepad_data_fetcher.h"
 #include "device/gamepad/gamepad_pad_state_provider.h"
 #include "device/gamepad/gamepad_platform_data_fetcher_linux.h"
-#include "ui/aura/client/focus_client.h"
 #include "ui/aura/window.h"
 
 namespace exo {
 namespace {
 
 constexpr double kGamepadButtonValueEpsilon = 0.001;
 bool GamepadButtonValuesAreEqual(double a, double b) {
   return fabs(a - b) < kGamepadButtonValueEpsilon;
 }
 
@@ skipping 169 matching lines @@
               base::Bind(CreateGamepadPlatformDataFetcher)) {}
 
 Gamepad::Gamepad(GamepadDelegate* delegate,
                  base::SingleThreadTaskRunner* polling_task_runner,
                  CreateGamepadDataFetcherCallback create_fetcher_callback)
     : delegate_(delegate), weak_factory_(this) {
   gamepad_change_fetcher_ = new ThreadSafeGamepadChangeFetcher(
       base::Bind(&Gamepad::ProcessGamepadChanges, weak_factory_.GetWeakPtr()),
       create_fetcher_callback, polling_task_runner);
 
-  aura::client::FocusClient* focus_client =
-      aura::client::GetFocusClient(ash::Shell::GetPrimaryRootWindow());
-  focus_client->AddObserver(this);
-  OnWindowFocused(focus_client->GetFocusedWindow(), nullptr);
+  auto* helper = WMHelper::GetInstance();
+  helper->AddFocusObserver(this);
+  OnWindowFocused(helper->GetFocusedWindow(), nullptr);
 }
 
 Gamepad::~Gamepad() {
   // Disable polling. Since ThreadSafeGamepadChangeFetcher are reference
   // counted, we can safely have it shut down after Gamepad has been destroyed.
   gamepad_change_fetcher_->EnablePolling(false);
 
   delegate_->OnGamepadDestroying(this);
-  aura::client::GetFocusClient(ash::Shell::GetPrimaryRootWindow())
-      ->RemoveObserver(this);
+  WMHelper::GetInstance()->RemoveFocusObserver(this);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // aura::client::FocusChangeObserver overrides:
 
 void Gamepad::OnWindowFocused(aura::Window* gained_focus,
                               aura::Window* lost_focus) {
   DCHECK(thread_checker_.CalledOnValidThread());
   Surface* target = nullptr;
   if (gained_focus) {
@@ skipping 48 matching lines @@
       delegate_->OnButton(button_id, new_button.pressed, new_button.value);
     }
   }
   if (send_frame)
     delegate_->OnFrame();
 
   pad_state_ = new_pad;
 }
 
 }  // namespace exo