Fix white flash when user sings out and wallpaper animation regression

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 2d49b4d18cd27d7c67b7d577080e3b74d7c976d5..ad83164b5acb153369322285543ce7eb094d27f9 100644
--- a/ash/desktop_background/desktop_background_controller.cc
+++ b/ash/desktop_background/desktop_background_controller.cc
@@ -106,7 +106,6 @@ DesktopBackgroundController::DesktopBackgroundController()
       desktop_background_mode_(BACKGROUND_SOLID_COLOR),
       background_color_(kTransparentColor),
       weak_ptr_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
-  InstallComponentForAllWindows();
 }
 
 DesktopBackgroundController::~DesktopBackgroundController() {
@@ -213,22 +212,10 @@ void DesktopBackgroundController::CancelPendingWallpaperOperation() {
 void DesktopBackgroundController::SetDesktopBackgroundSolidColorMode(
     SkColor color) {
   background_color_ = color;
-  if (desktop_background_mode_ != BACKGROUND_SOLID_COLOR) {
+  if (desktop_background_mode_ != BACKGROUND_SOLID_COLOR)
     desktop_background_mode_ = BACKGROUND_SOLID_COLOR;
-    InstallComponentForAllWindows();
-    return;
-  }
 
-  Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
-  for (Shell::RootWindowList::iterator iter = root_windows.begin();
-       iter != root_windows.end(); ++iter) {
-    aura::RootWindow* root_window = *iter;
-    internal::DesktopBackgroundWidgetController* component = root_window->
-        GetProperty(internal::kWindowDesktopComponent);
-    DCHECK(component);
-    DCHECK(component->layer());
-    component->layer()->SetColor(background_color_ );
-  }
+  InstallComponentForAllWindows();
 }
 
 void DesktopBackgroundController::CreateEmptyWallpaper() {
@@ -260,23 +247,8 @@ void DesktopBackgroundController::OnWindowDestroying(aura::Window* window) {
 void DesktopBackgroundController::SetDesktopBackgroundImageMode() {
   if (desktop_background_mode_ != BACKGROUND_IMAGE) {
     desktop_background_mode_ = BACKGROUND_IMAGE;
-    InstallComponentForAllWindows();
-    return;
-  }
-
-  Shell::RootWindowList root_windows = Shell::GetAllRootWindows();
-  for (Shell::RootWindowList::iterator iter = root_windows.begin();
-      iter != root_windows.end(); ++iter) {
-    aura::RootWindow* root_window = *iter;
-    internal::DesktopBackgroundWidgetController* component = root_window->
-        GetProperty(internal::kWindowDesktopComponent);
-    DCHECK(component);
-    DCHECK(component->widget());
-    aura::Window* window = component->widget()->GetNativeView();
-    gfx::Rect bounds = window->bounds();
-    window->SchedulePaintInRect(gfx::Rect(0, 0,
-                                          bounds.width(), bounds.height()));
   }
+  InstallComponentForAllWindows();
 }
 
 void DesktopBackgroundController::OnWallpaperLoadCompleted(
@@ -311,6 +283,7 @@ void DesktopBackgroundController::InstallComponent(
       views::Widget* widget = internal::CreateDesktopBackground(root_window,
                                                                 container_id);
       component = new internal::DesktopBackgroundWidgetController(widget);
+      root_window_component_map_[root_window] = component;
       break;
     }
     case BACKGROUND_SOLID_COLOR: {
@@ -328,6 +301,12 @@ void DesktopBackgroundController::InstallComponent(
     // First time for this root window
     root_window->AddObserver(this);
   }
+}
+
+void DesktopBackgroundController::SetComponentForRootWindow(
+    aura::RootWindow* root_window) {
+  internal::DesktopBackgroundWidgetController* component =
+      root_window_component_map_[root_window];
   root_window->SetProperty(internal::kWindowDesktopComponent, component);
 }