Restore to user selected wallpaper after browser crash

ash/shell.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/shell.h"
 
 #include <algorithm>
 
 #include "ash/app_list/app_list.h"
 #include "ash/ash_switches.h"
@@ skipping 580 matching lines @@
   }
   if (!status_widget_)
     status_widget_ = internal::CreateStatusArea(tray_.get());
 
   aura::Window* default_container =
       GetContainer(internal::kShellWindowId_DefaultContainer);
   launcher_.reset(new Launcher(default_container));
 
   // This controller needs to be set before SetupManagedWindowMode.
   desktop_background_controller_.reset(new DesktopBackgroundController);
+  if (delegate_.get())
+    user_wallpaper_delegate_.reset(delegate_->CreateUserWallpaperDelegate());
+  desktop_background_controller_->SetDesktopBackgroundImageMode(
+      GetWallpaper(user_wallpaper_delegate_->GetUserWallpaperIndex()));

[flackr, 2012/03/21 17:44:20]

Seems this would be equivalent to:
desktop_background_controller_->OnUserLoginOrSwitchToImageMode(). Can we use
that?

[bshe, 2012/03/22 02:16:03]

Yes and no. Ideally, they should be equivalent. But since we have this issue
117244 not been fixed, we need to create the background widget when shell
initialize and only destroy it when shell got destroyed. So here, I need to use
SetDesktopBackgroundImageMode to initialized the background widget and only
update it in OnDesktopBackgroundChanged function.

 
   InitLayoutManagers();
 
   if (!command_line->HasSwitch(switches::kAuraNoShadows)) {
     resize_shadow_controller_.reset(new internal::ResizeShadowController());
     shadow_controller_.reset(new internal::ShadowController());
   }
 
   focus_cycler_.reset(new internal::FocusCycler());
   focus_cycler_->AddWidget(status_widget_);
@@ skipping 134 matching lines @@
 
   aura::Window* default_container =
       GetContainer(internal::kShellWindowId_DefaultContainer);
   // Workspace manager has its own layout managers.
   workspace_controller_.reset(
       new internal::WorkspaceController(default_container));
   workspace_controller_->workspace_manager()->set_shelf(shelf_layout_manager);
 
   // Ensure launcher is visible.
   launcher_->widget()->Show();
-
-  // Create the desktop background image.
-  desktop_background_controller_->SetDefaultDesktopBackgroundImage();
 }
 
 void Shell::DisableWorkspaceGridLayout() {
   if (workspace_controller_.get())
     workspace_controller_->workspace_manager()->set_grid_size(0);
 }
 
 }  // namespace ash