chromeos: Fix shelf appearing at login screen under mash

ash/common/wm_shell.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/common/wm_shell.h"
 
 #include <utility>
 
 #include "ash/common/accelerators/accelerator_controller.h"
 #include "ash/common/accelerators/ash_focus_manager_factory.h"
@@ skipping 133 matching lines @@
 void WmShell::CreateShelf() {
   // Must occur after SessionStateDelegate creation and user login.
   DCHECK(GetSessionStateDelegate());
   DCHECK_GT(GetSessionStateDelegate()->NumberOfLoggedInUsers(), 0);
   CreateShelfDelegate();
 
   for (WmWindow* root_window : GetAllRootWindows())
     root_window->GetRootWindowController()->CreateShelf();
 }
 
-void WmShell::ShowShelf() {
-  for (WmWindow* root_window : GetAllRootWindows())
-    root_window->GetRootWindowController()->ShowShelf();
-}
-
 void WmShell::CreateShelfDelegate() {
   // May be called multiple times as shelves are created and destroyed.
   if (shelf_delegate_)
     return;
   // Must occur after SessionStateDelegate creation and user login because
   // Chrome's implementation of ShelfDelegate assumes it can get information
   // about multi-profile login state.
   DCHECK(GetSessionStateDelegate());
   DCHECK_GT(GetSessionStateDelegate()->NumberOfLoggedInUsers(), 0);
   shelf_delegate_.reset(delegate_->CreateShelfDelegate(shelf_model()));
@@ skipping 96 matching lines @@
       system_tray_notifier_(base::MakeUnique<SystemTrayNotifier>()),
       wallpaper_delegate_(delegate_->CreateWallpaperDelegate()),
       window_cycle_controller_(base::MakeUnique<WindowCycleController>()),
       window_selector_controller_(
           base::MakeUnique<WindowSelectorController>()) {
 #if defined(OS_CHROMEOS)
   brightness_control_delegate_.reset(new system::BrightnessControllerChromeos);
   keyboard_brightness_control_delegate_.reset(new KeyboardBrightnessController);
   vpn_list_ = base::MakeUnique<VpnList>();
 #endif
+  session_controller_->AddSessionStateObserver(this);
 }
 
-WmShell::~WmShell() {}
+WmShell::~WmShell() {
+  session_controller_->RemoveSessionStateObserver(this);
+}
 
 WmRootWindowController* WmShell::GetPrimaryRootWindowController() {
   return GetPrimaryRootWindow()->GetRootWindowController();
 }
 
 WmWindow* WmShell::GetRootWindowForNewWindows() {
   if (scoped_root_window_for_new_windows_)
     return scoped_root_window_for_new_windows_;
   return root_window_for_new_windows_;
 }
@@ skipping 120 matching lines @@
 
 void WmShell::DeleteToastManager() {
   toast_manager_.reset();
 }
 
 void WmShell::SetAcceleratorController(
     std::unique_ptr<AcceleratorController> accelerator_controller) {
   accelerator_controller_ = std::move(accelerator_controller);
 }
 
+void WmShell::SessionStateChanged(session_manager::SessionState state) {
+  // Create the shelf when a session becomes active. It's safe to do this
+  // multiple times (e.g. initial login vs. multiprofile add session).
+  if (state == session_manager::SessionState::ACTIVE)
+    CreateShelf();
+}
+
 }  // namespace ash