mash: Migrate wallpaper controllers to ash/common.

ash/mus/bridge/wm_shell_mus.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/mus/bridge/wm_shell_mus.h"
 
 #include <utility>
 
 #include "ash/common/accelerators/accelerator_controller.h"
 #include "ash/common/keyboard/keyboard_ui.h"
@@ skipping 95 matching lines @@
 
 }  // namespace
 
 WmShellMus::WmShellMus(
     std::unique_ptr<ShellDelegate> shell_delegate,
     WindowManager* window_manager,
     views::PointerWatcherEventRouter* pointer_watcher_event_router)
     : WmShell(std::move(shell_delegate)),
       window_manager_(window_manager),
       pointer_watcher_event_router_(pointer_watcher_event_router),
-      session_state_delegate_(new SessionStateDelegateStub) {
+      session_state_delegate_(new SessionStateDelegateStub),
+      blocking_pool_(
+          new base::SequencedWorkerPool(3,

[James Cook, 2016/09/07 21:27:05]

Do you need to call blocking_pool_->Shutdown()?

Also, I'm not too familiar with SequencedWorkerPool. You might want to have
someone else look at this part. I seem to recall sky@ had an issue with shutdown
leaks doing something similar to this (even with Shutdown). See
https://codereview.chromium.org/2296973002

Also nit: It would be nice to comment what "3" is.

[msw, 2016/09/07 22:28:24]

Done; that fixes mash_unittests. I'll also ask Scott to check this.

[sky, 2016/09/08 04:15:22]

I believe you want to make it so you can inject a sequencedworkerpool for tests.
See base::SequencedWorkerPoolOwner for details on all the reasons you may run
into problems if you don't use SequencedWorkerPoolOwner in tests.

[msw, 2016/09/08 19:52:15]

Done; I moved Shell::blocking_pool_ to WmShell, made WindowManagerApplication
create/own the pool for mash (except in tests, afaict), and made WmTestHelper
own a SequencedWorkerPoolOwner for tests. This required some
WindowManager[Application] initialization plumbing. Please let me know if you
see a better approach.

+                                        "MashBlocking",
+                                        base::TaskPriority::USER_VISIBLE)) {
   window_tree_client()->AddObserver(this);
   WmShell::Set(this);
 
   uint16_t accelerator_namespace_id = 0u;
   const bool add_result =
       window_manager->GetNextAcceleratorNamespaceId(&accelerator_namespace_id);
   // WmShellMus is created early on, so that this should always succeed.
   DCHECK(add_result);
   accelerator_controller_delegate_.reset(
       new AcceleratorControllerDelegateMus(window_manager_->connector()));
@@ skipping 272 matching lines @@
 void WmShellMus::RemovePointerWatcher(views::PointerWatcher* watcher) {
   pointer_watcher_event_router_->RemovePointerWatcher(watcher);
 }
 
 bool WmShellMus::IsTouchDown() {
   // TODO: implement me, http://crbug.com/634967.
   // NOTIMPLEMENTED is too spammy here.
   return false;
 }
 
+base::SequencedWorkerPool* WmShellMus::GetBlockingPool() {
+  return blocking_pool_.get();
+}
+
 #if defined(OS_CHROMEOS)
 void WmShellMus::ToggleIgnoreExternalKeyboard() {
   NOTIMPLEMENTED();
 }
 #endif  // defined(OS_CHROMEOS)
 
 ui::WindowTreeClient* WmShellMus::window_tree_client() {
   return window_manager_->window_tree_client();
 }
 
@@ skipping 18 matching lines @@
                     OnWindowActivated(gained_active, lost_active));
 }
 
 void WmShellMus::OnDidDestroyClient(ui::WindowTreeClient* client) {
   DCHECK_EQ(window_tree_client(), client);
   client->RemoveObserver(this);
 }
 
 }  // namespace mus
 }  // namespace ash