chromeos: Refactor shelf to create ShelfView earlier in startup

ash/shelf/shelf_layout_manager.cc

 // Copyright (c) 2012 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/shelf/shelf_layout_manager.h"
 
 #include <algorithm>
 #include <cmath>
 #include <vector>
 
@@ skipping 216 matching lines @@
       return SHELF_AUTO_HIDE;
     case SHELF_AUTO_HIDE_BEHAVIOR_NEVER:
       return SHELF_VISIBLE;
     case SHELF_AUTO_HIDE_ALWAYS_HIDDEN:
       return SHELF_HIDDEN;
   }
   return SHELF_VISIBLE;
 }
 
 void ShelfLayoutManager::UpdateVisibilityState() {
-  // Bail out early before the shelf is initialized or after it is destroyed.
-  WmWindow* shelf_window = WmWindow::Get(shelf_widget_->GetNativeWindow());
-  if (in_shutdown_ || !wm_shelf_->IsShelfInitialized() || !shelf_window)
+  // Shelf is not available before login.
+  // TODO: Remove this when webui fake-shelf is replaced with views.

[msw, 2017/05/16 22:42:00]

nit: cite the bug, consider "  // TODO(crbug.com/######): Remove this when
login/lock use the real shelf." or similar? ditto below (line 896)

[James Cook, 2017/05/17 16:16:12]

Done.

+  if (!Shell::Get()->session_controller()->IsActiveUserSessionStarted())
     return;
+
+  // Bail out early after shelf is destroyed.
+  aura::Window* shelf_window = shelf_widget_->GetNativeWindow();
+  if (in_shutdown_ || !shelf_window)

[James Cook, 2017/05/16 21:32:35]

It's unclear if the shelf_window check is needed but I don't want to touch it.

[msw, 2017/05/16 22:42:00]

Acknowledged.

+    return;
+
   if (state_.IsScreenLocked() || state_.IsAddingSecondaryUser()) {
     SetState(SHELF_VISIBLE);
   } else if (Shell::Get()->screen_pinning_controller()->IsPinned()) {
     SetState(SHELF_HIDDEN);
   } else {
     // TODO(zelidrag): Verify shelf drag animation still shows on the device
     // when we are in SHELF_AUTO_HIDE_ALWAYS_HIDDEN.
     wm::WorkspaceWindowState window_state(
-        shelf_window->GetRootWindowController()->GetWorkspaceWindowState());
+        RootWindowController::ForWindow(shelf_window)
+            ->GetWorkspaceWindowState());
 
     switch (window_state) {
       case wm::WORKSPACE_WINDOW_STATE_FULL_SCREEN: {
         if (IsShelfAutoHideForFullscreenMaximized()) {
           SetState(SHELF_AUTO_HIDE);
         } else if (IsShelfHiddenForFullscreen()) {
           SetState(SHELF_HIDDEN);
         } else {
           // The shelf is sometimes not hidden when in immersive fullscreen.
           // Force the shelf to be auto hidden in this case.
@@ skipping 617 matching lines @@
     if (window->IsVisible() && !IsAppListWindow(window) &&
         root->Contains(window)) {
       return true;
     }
   }
   return false;
 }
 
 ShelfAutoHideState ShelfLayoutManager::CalculateAutoHideState(
     ShelfVisibilityState visibility_state) const {
-  if (visibility_state != SHELF_AUTO_HIDE || !wm_shelf_->IsShelfInitialized())
+  // Shelf is not available before login.
+  // TODO: Remove this when webui fake-shelf is replaced with views.
+  if (!Shell::Get()->session_controller()->IsActiveUserSessionStarted())
+    return SHELF_AUTO_HIDE_HIDDEN;
+
+  if (visibility_state != SHELF_AUTO_HIDE)
     return SHELF_AUTO_HIDE_HIDDEN;
 
   if (shelf_widget_->IsShowingAppList())
     return SHELF_AUTO_HIDE_SHOWN;
 
   if (shelf_widget_->status_area_widget() &&
       shelf_widget_->status_area_widget()->ShouldShowShelf())
     return SHELF_AUTO_HIDE_SHOWN;
 
   if (shelf_widget_->IsShowingContextMenu())
@@ skipping 243 matching lines @@
   gesture_drag_status_ = GESTURE_DRAG_NONE;
 }
 
 void ShelfLayoutManager::CancelGestureDrag() {
   gesture_drag_status_ = GESTURE_DRAG_CANCEL_IN_PROGRESS;
   UpdateVisibilityState();
   gesture_drag_status_ = GESTURE_DRAG_NONE;
 }
 
 }  // namespace ash