Re-reland: chromeos: Fix shelf appearing at login screen under mash

ash/common/shelf/shelf_widget.cc

 // Copyright 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/common/shelf/shelf_widget.h"
 
 #include "ash/common/focus_cycler.h"
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/shelf/app_list_button.h"
@@ skipping 313 matching lines @@
   GetContentsView()->AddChildView(shelf_view_);
   return shelf_view_;
 }
 
 void ShelfWidget::PostCreateShelf() {
   SetFocusCycler(WmShell::Get()->focus_cycler());
 
   // Ensure the newly created |shelf_| gets current values.
   background_animator_.Initialize(this);
 
+  // TODO(jamescook): The IsActiveUserSessionStarted() check may not be needed
+  // because the shelf is only created after the first user session is active.
+  // The ShelfView seems to always be visible after login. At the lock screen
+  // the shelf is hidden because its container is hidden. During auto-hide it is
+  // hidden because ShelfWidget is transparent. Some of the ShelfView visibility
+  // code could be simplified. http://crbug.com/674773
   shelf_view_->SetVisible(
       WmShell::Get()->GetSessionStateDelegate()->IsActiveUserSessionStarted());
   shelf_layout_manager_->LayoutShelf();
   shelf_layout_manager_->UpdateAutoHideState();
   Show();
 }
 
 bool ShelfWidget::IsShelfVisible() const {
   return shelf_view_ && shelf_view_->visible();
 }
 
-void ShelfWidget::SetShelfVisibility(bool visible) {
-  if (shelf_view_)
-    shelf_view_->SetVisible(visible);
-}
-
 bool ShelfWidget::IsShowingAppList() const {
   return GetAppListButton() && GetAppListButton()->is_showing_app_list();
 }
 
 bool ShelfWidget::IsShowingContextMenu() const {
   return shelf_view_ && shelf_view_->IsShowingMenu();
 }
 
 bool ShelfWidget::IsShowingOverflowBubble() const {
   return shelf_view_ && shelf_view_->IsShowingOverflowBubble();
@@ skipping 21 matching lines @@
     background_animator_.RemoveObserver(status_area_widget_);
     WmShell::Get()->focus_cycler()->RemoveWidget(status_area_widget_);
     status_area_widget_->Shutdown();
     status_area_widget_ = nullptr;
   }
 
   CloseNow();
 }
 
 void ShelfWidget::UpdateIconPositionForPanel(WmWindow* panel) {
+  if (!shelf_view_)
+    return;
+
   WmWindow* shelf_window = WmLookup::Get()->GetWindowForWidget(this);
   shelf_view_->UpdatePanelIconPosition(
       panel->GetIntProperty(WmWindowProperty::SHELF_ID),
       shelf_window->ConvertRectFromScreen(panel->GetBoundsInScreen())
           .CenterPoint());
 }
 
 gfx::Rect ShelfWidget::GetScreenBoundsOfItemIconForWindow(WmWindow* window) {
+  // Window animations can be triggered during session restore before the shelf
+  // view is created.

[msw, 2017/01/11 00:54:54]

nit: "In that case, return default empty bounds" (or similar).

[James Cook, 2017/01/11 17:03:48]

Done.

+  if (!shelf_view_)
+    return gfx::Rect();

[James Cook, 2017/01/11 00:39:50]

This is the crash fix. It results in the window being animated to the
bottom-left corner of the screen (or a different corner, depending on the shelf
alignment setting).

+
   ShelfID id = window->GetIntProperty(WmWindowProperty::SHELF_ID);
   gfx::Rect bounds(shelf_view_->GetIdealBoundsOfItemIcon(id));
   gfx::Point screen_origin;
   views::View::ConvertPointToScreen(shelf_view_, &screen_origin);
   return gfx::Rect(screen_origin.x() + bounds.x(),
                    screen_origin.y() + bounds.y(), bounds.width(),
                    bounds.height());
 }
 
 AppListButton* ShelfWidget::GetAppListButton() const {
@@ skipping 18 matching lines @@
   if (shelf_view_)
     shelf_view_->UpdateShelfItemBackground(alpha);
 }
 
 void ShelfWidget::WillDeleteShelfLayoutManager() {
   shelf_layout_manager_->RemoveObserver(this);
   shelf_layout_manager_ = nullptr;
 }
 
 }  // namespace ash