Use a #fefefe solid color wallpaper background before user login for GAIA login flow

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 <string>
 
 #include "ash/accelerators/focus_manager_factory.h"
@@ skipping 226 matching lines @@
 }
 
 // This dummy class is used for shell unit tests. We dont have chrome delegate
 // in these tests.
 class DummyUserWallpaperDelegate : public UserWallpaperDelegate {
  public:
   DummyUserWallpaperDelegate() {}
 
   virtual ~DummyUserWallpaperDelegate() {}
 
-  virtual void SetLoggedInUserWallpaper() OVERRIDE {
+  virtual void InitializeWallpaper() OVERRIDE {
     ash::Shell::GetInstance()->desktop_background_controller()->
         CreateEmptyWallpaper();
   }
 
   virtual void OpenSetWallpaperPage() OVERRIDE {
   }
 
   virtual bool CanOpenSetWallpaperPage() OVERRIDE {
     return false;
   }
@@ skipping 545 matching lines @@
   focus_cycler_->AddWidget(status_area_widget_);
 
   if (!delegate_.get() || delegate_->IsUserLoggedIn())
     CreateLauncher();
 
   // Force a layout.
   root_window->layout_manager()->OnWindowResized();
 
   // It needs to be created after OnWindowResized has been called, otherwise the
   // widget will not paint when restoring after a browser crash.
-  user_wallpaper_delegate_->SetLoggedInUserWallpaper();
+  user_wallpaper_delegate_->InitializeWallpaper();
 
   window_modality_controller_.reset(new internal::WindowModalityController);
   AddRootWindowEventFilter(window_modality_controller_.get());
 
   visibility_controller_.reset(new internal::VisibilityController);
   aura::client::SetVisibilityClient(root_window, visibility_controller_.get());
 
   drag_drop_controller_.reset(new internal::DragDropController);
   aura::client::SetDragDropClient(root_window, drag_drop_controller_.get());
 
@@ skipping 225 matching lines @@
     panel_container->SetLayoutManager(panel_layout_manager_);
   }
 }
 
 void Shell::DisableWorkspaceGridLayout() {
   if (workspace_controller_.get())
     workspace_controller_->workspace_manager()->set_grid_size(0);
 }
 
 }  // namespace ash