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

ash/desktop_background/desktop_background_controller.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/desktop_background/desktop_background_controller.h"
 
 #include "ash/desktop_background/desktop_background_view.h"
 #include "ash/shell.h"
 #include "ash/shell_factory.h"
 #include "ash/shell_window_ids.h"
@@ skipping 121 matching lines @@
 }
 
 void DesktopBackgroundController::SetLoggedInUserWallpaper() {
   int index = Shell::GetInstance()->user_wallpaper_delegate()->
       GetUserWallpaperIndex();
   // We should not change background when index is invalid. For instance, at
   // login screen or stub_user login.
   if (index == ash::GetInvalidWallpaperIndex()) {
     CreateEmptyWallpaper();
     return;
+  } else if (index == ash::GetSolidColorIndex()) {

[Nikita (slow), 2012/06/04 18:23:03]

I'm a bit confused why this happens inside SetLoggedInUserWallpaper() method.

Comment says
  // Loads logged in user wallpaper asynchronously and sets to current wallpaper
  // after loaded.

Given the fact that this now handles any wallpaper related initialization on
boot (both normal boot + after crash), makes sense to rename this method to
something like InitializeWallpaper?

[bshe, 2012/06/08 15:06:30]

It is also used when user toggle background color mode in
ash/accelerators/accelerator_controller.cc:163. But I agree rename it to
InitializeWallpaper makes more sense.

On 2012/06/04 18:23:03, Nikita Kostylev wrote:

+    SetDesktopBackgroundSolidColorMode();
+    return;
   }
 
   SetDefaultWallpaper(index);
 }
 
 void DesktopBackgroundController::SetDesktopBackgroundSolidColorMode() {
   // Set a solid black background.
   // TODO(derat): Remove this in favor of having the compositor only clear the
   // viewport when there are regions not covered by a layer:
   // http://crbug.com/113445
   ui::Layer* background_layer = new ui::Layer(ui::LAYER_SOLID_COLOR);
-  background_layer->SetColor(SK_ColorBLACK);
+  background_layer->SetColor(SK_ColorWallpaperGray);

[Nikita (slow), 2012/06/04 18:23:03]

I think that it makes sense to pass color as a parameter.

[bshe, 2012/06/08 15:06:30]

Done.

   root_window_->GetChildById(
       internal::kShellWindowId_DesktopBackgroundContainer)->
       layer()->Add(background_layer);
   GetRootWindowLayoutManager(root_window_)->SetBackgroundLayer(
       background_layer);
   GetRootWindowLayoutManager(root_window_)->SetBackgroundWidget(NULL);
   desktop_background_mode_ = BACKGROUND_SOLID_COLOR;
 }
 
 void DesktopBackgroundController::SetDesktopBackgroundImageMode(
@@ skipping 15 matching lines @@
   wallpaper_op_ = NULL;
 }
 
 void DesktopBackgroundController::CreateEmptyWallpaper() {
   gfx::ImageSkia dummy;
   internal::CreateDesktopBackground(dummy, CENTER, root_window_);
   desktop_background_mode_ = BACKGROUND_IMAGE;
 }
 
 }  // namespace ash