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

ash/desktop_background/desktop_background_controller.cc

Index: ash/desktop_background/desktop_background_controller.cc
diff --git a/ash/desktop_background/desktop_background_controller.cc b/ash/desktop_background/desktop_background_controller.cc
index 5994bf2326736021607071c81c048edc2cb3a8ed..e9d20af030f9672a61fc92fb609150f46a2c22fb 100644
--- a/ash/desktop_background/desktop_background_controller.cc
+++ b/ash/desktop_background/desktop_background_controller.cc
@@ -150,7 +150,7 @@ void DesktopBackgroundController::SetDesktopBackgroundSolidColorMode() {
   // 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);
@@ -180,9 +180,8 @@ void DesktopBackgroundController::OnWallpaperLoadCompleted(
 }
 
 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