Add persisted preference for projection touch HUD

ash/root_window_controller.cc

Index: ash/root_window_controller.cc
diff --git a/ash/root_window_controller.cc b/ash/root_window_controller.cc
index ba20f5834e0bf87f04a86edb151b4e80957d664e..7ba969a4836e0f21cd69747d9f9f8ed6dd3b24eb 100644
--- a/ash/root_window_controller.cc
+++ b/ash/root_window_controller.cc
@@ -203,18 +203,6 @@ RootWindowController* RootWindowController::ForActiveRootWindow() {
   return GetRootWindowController(Shell::GetActiveRootWindow());
 }
 
-void RootWindowController::EnableTouchHudProjection() {
-  if (touch_hud_projection_)
-    return;
-  set_touch_hud_projection(new TouchHudProjection(root_window_.get()));
-}
-
-void RootWindowController::DisableTouchHudProjection() {
-  if (!touch_hud_projection_)
-    return;
-  touch_hud_projection_->Remove();
-}
-
 void RootWindowController::SetWallpaperController(
     DesktopBackgroundWidgetController* controller) {
   wallpaper_controller_.reset(controller);
@@ -228,6 +216,8 @@ void RootWindowController::SetAnimatingWallpaperController(
 }
 
 void RootWindowController::Shutdown() {
+  Shell::GetInstance()->RemoveShellObserver(this);
+
   if (animating_wallpaper_controller_.get())
     animating_wallpaper_controller_->StopAnimating();
   wallpaper_controller_.reset();
@@ -292,6 +282,8 @@ void RootWindowController::Init(bool first_run_after_boot) {
       GetSystemModalLayoutManager(NULL)->has_modal_background()) {
     GetSystemModalLayoutManager(NULL)->CreateModalBackground();
   }
+
+  Shell::GetInstance()->AddShellObserver(this);
 }
 
 void RootWindowController::ShowLauncher() {
@@ -308,10 +300,6 @@ void RootWindowController::OnLauncherCreated() {
     docked_layout_manager_->SetLauncher(shelf_->launcher());
 }
 
-void RootWindowController::OnLoginStateChanged(user::LoginStatus status) {
-  shelf_->shelf_layout_manager()->UpdateVisibilityState();
-}
-
 void RootWindowController::UpdateAfterLoginStatusChange(
     user::LoginStatus status) {
   if (shelf_->status_area_widget())
@@ -700,5 +688,28 @@ void RootWindowController::CreateContainersInRootWindow(
                   "PowerButtonAnimationContainer", root_window) ;
 }
 
+void RootWindowController::EnableTouchHudProjection() {
+  if (touch_hud_projection_)
+    return;
+  set_touch_hud_projection(new TouchHudProjection(root_window_.get()));
+}
+
+void RootWindowController::DisableTouchHudProjection() {
+  if (!touch_hud_projection_)
+    return;
+  touch_hud_projection_->Remove();
+}
+
+void RootWindowController::OnLoginStateChanged(user::LoginStatus status) {
+  shelf_->shelf_layout_manager()->UpdateVisibilityState();
+}
+
+void RootWindowController::OnTouchHudProjectionToggled(bool enabled) {
+  if (enabled)
+    EnableTouchHudProjection();
+  else
+    DisableTouchHudProjection();
+}
+
 }  // namespace internal
 }  // namespace ash