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 132 matching lines @@
 
   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 11:23:04]

I'm not sure whether this affects other code paths / cases?

[bshe, 2012/06/04 13:46:22]

I think we dont use the solid color background at all before this CL. We will
use it more for next version of wallpaper manager. So I will change this
function to take a SkColor parameter later.

Here, I just want to minimize the change. But as you mentioned, make empty
wallpaper transparent can also work. If we want to go that path, I guess this cl
is not necessary then.

On 2012/06/04 11:23:04, Nikita Kostylev wrote:

   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(
     scoped_refptr<WallpaperOperation> wo) {
   GetRootWindowLayoutManager(root_window_)->SetBackgroundLayer(NULL);
   if(wo->wallpaper()) {
     internal::CreateDesktopBackground(
         *wo->wallpaper(), wo->wallpaper_layout(), root_window_);
     desktop_background_mode_ = BACKGROUND_IMAGE;
   }
 }
 
 void DesktopBackgroundController::OnWallpaperLoadCompleted(
     scoped_refptr<WallpaperOperation> wo) {
   SetDesktopBackgroundImageMode(wo);
   previous_index_ = wo->index();
 
   DCHECK(wo.get() == wallpaper_op_.get());
   wallpaper_op_ = NULL;
 }
 
 void DesktopBackgroundController::CreateEmptyWallpaper() {
-  gfx::ImageSkia dummy;
-  internal::CreateDesktopBackground(dummy, CENTER, root_window_);
-  desktop_background_mode_ = BACKGROUND_IMAGE;
+  SetDesktopBackgroundSolidColorMode();
+  desktop_background_mode_ = BACKGROUND_SOLID_COLOR;
 }
 
 }  // namespace ash