cros: WallpaperController reparent based on session state

ash/wallpaper/wallpaper_controller.cc

Index: ash/wallpaper/wallpaper_controller.cc
diff --git a/ash/wallpaper/wallpaper_controller.cc b/ash/wallpaper/wallpaper_controller.cc
index 9c0ecc465970bb47cf460edb0315d70a365bf41d..15f2cc03cdf7ace5fa513b7cf1dcb48d6ec4e02f 100644
--- a/ash/wallpaper/wallpaper_controller.cc
+++ b/ash/wallpaper/wallpaper_controller.cc
@@ -168,20 +168,6 @@ void WallpaperController::CreateEmptyWallpaper() {
   InstallDesktopControllerForAllWindows();
 }
 
-bool WallpaperController::MoveToLockedContainer() {
-  if (locked_)
-    return false;
-  locked_ = true;
-  return ReparentWallpaper(GetWallpaperContainerId(true));
-}
-
-bool WallpaperController::MoveToUnlockedContainer() {
-  if (!locked_)
-    return false;
-  locked_ = false;
-  return ReparentWallpaper(GetWallpaperContainerId(false));
-}
-
 void WallpaperController::OnDisplayConfigurationChanged() {
   gfx::Size max_display_size = GetMaxDisplaySizeInNative();
   if (current_max_display_size_ != max_display_size) {
@@ -215,6 +201,11 @@ void WallpaperController::OnRootWindowAdded(WmWindow* root_window) {
 void WallpaperController::OnSessionStateChanged(
     session_manager::SessionState state) {
   CalculateWallpaperColors();
+
+  if (state == session_manager::SessionState::ACTIVE)
+    MoveToUnlockedContainer();
+  else
+    MoveToLockedContainer();
 }
 
 // static
@@ -401,4 +392,20 @@ bool WallpaperController::ShouldCalculateColors() const {
          !image.isNull();
 }
 
+bool WallpaperController::MoveToLockedContainer() {
+  if (locked_)
+    return false;
+
+  locked_ = true;
+  return ReparentWallpaper(GetWallpaperContainerId(true));
+}
+
+bool WallpaperController::MoveToUnlockedContainer() {
+  if (!locked_)
+    return false;
+
+  locked_ = false;
+  return ReparentWallpaper(GetWallpaperContainerId(false));
+}
+
 }  // namespace ash