ash: Use SessionController instead of SessionStateDelegate

ash/common/shelf/shelf_locking_manager.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/shelf/shelf_locking_manager.h"
 
-#include "ash/common/session/session_state_delegate.h"
+#include "ash/common/session/session_controller.h"
 #include "ash/common/shelf/wm_shelf.h"
 #include "ash/common/wm_shell.h"
 #include "ash/shell.h"
 
 namespace ash {
 
-ShelfLockingManager::ShelfLockingManager(WmShelf* shelf) : shelf_(shelf) {
+ShelfLockingManager::ShelfLockingManager(WmShelf* shelf)
+    : shelf_(shelf), stored_alignment_(shelf->GetAlignment()) {

[xiyuan, 2017/03/17 07:08:15]

Initialize |stored_alignment_| with the current alignment of |shelf_|, caught by
ShelfWidgetTestWithInitializer.CreateLockedShelf.

New test setup fires SessionStateChanged and mocks a user has signed in. Thus
ShelfLockingManager::SessionStateChanged would set |shelf_| alignment to
|stored_alignment_|. Without this, |shelf_| alignment is initialized to
SHELF_ALIGNMENT_BOTTOM. This would also happen in production code and could
trigger unnecessary workspace change.

[James Cook, 2017/03/17 17:14:35]

msw, can you look at this piece of the CL? I think warx@ recently had a bug with
shelf locking during login.

(Also, if you initialize this here please remove the initialization from the
header file.)

(Also also, DCHECK(shelf_) while you're here.)

[msw, 2017/03/17 18:10:46]

This small part of the change lgtm (with James' suggestions). I'm not sure this
has any ramifications outside of test environments, but it certainly can't hurt.

[xiyuan, 2017/03/17 22:52:02]

Removed initialization from header and added DCHECK.

   WmShell::Get()->AddLockStateObserver(this);
-  SessionStateDelegate* delegate = WmShell::Get()->GetSessionStateDelegate();
+  SessionController* controller = WmShell::Get()->session_controller();
   session_locked_ =
-      delegate->GetSessionState() != session_manager::SessionState::ACTIVE;
-  screen_locked_ = delegate->IsScreenLocked();
-  delegate->AddSessionStateObserver(this);
+      controller->GetSessionState() != session_manager::SessionState::ACTIVE;
+  screen_locked_ = controller->IsScreenLocked();
+  controller->AddSessionStateObserver(this);
   Shell::GetInstance()->AddShellObserver(this);
 }
 
 ShelfLockingManager::~ShelfLockingManager() {
   WmShell::Get()->RemoveLockStateObserver(this);
-  WmShell::Get()->GetSessionStateDelegate()->RemoveSessionStateObserver(this);
+  WmShell::Get()->session_controller()->RemoveSessionStateObserver(this);
   Shell::GetInstance()->RemoveShellObserver(this);
 }
 
 void ShelfLockingManager::OnLockStateChanged(bool locked) {
   screen_locked_ = locked;
   UpdateLockedState();
 }
 
 void ShelfLockingManager::SessionStateChanged(
     session_manager::SessionState state) {
@@ skipping 11 matching lines @@
   const ShelfAlignment alignment = shelf_->GetAlignment();
   if (is_locked() && alignment != SHELF_ALIGNMENT_BOTTOM_LOCKED) {
     stored_alignment_ = alignment;
     shelf_->SetAlignment(SHELF_ALIGNMENT_BOTTOM_LOCKED);
   } else if (!is_locked() && alignment == SHELF_ALIGNMENT_BOTTOM_LOCKED) {
     shelf_->SetAlignment(stored_alignment_);
   }
 }
 
 }  // namespace ash