Draggable peeking/fullscreen launcher with transparent background.

ash/app_list/app_list_presenter_delegate.cc

Index: ash/app_list/app_list_presenter_delegate.cc
diff --git a/ash/app_list/app_list_presenter_delegate.cc b/ash/app_list/app_list_presenter_delegate.cc
index 01b2bcc52269651e19473af14eefae7b9fea4f0a..fc81a0ab465a3c04fea5fb455ba19c0594ed625a 100644
--- a/ash/app_list/app_list_presenter_delegate.cc
+++ b/ash/app_list/app_list_presenter_delegate.cc
@@ -119,13 +119,9 @@ void AppListPresenterDelegate::Init(app_list::AppListView* view,
 
 void AppListPresenterDelegate::OnShown(int64_t display_id) {
   is_visible_ = true;
-  // Update applist button status when app list visibility is changed.
   aura::Window* root_window =
       ShellPort::Get()->GetRootWindowForDisplayId(display_id);
-  AppListButton* app_list_button =
-      Shelf::ForWindow(root_window)->shelf_widget()->GetAppListButton();
-  if (app_list_button)
-    app_list_button->OnAppListShown();
+  Shell::Get()->OnAppListVisibilityChanged(is_visible_, root_window);
 }
 
 void AppListPresenterDelegate::OnDismissed() {
@@ -133,12 +129,9 @@ void AppListPresenterDelegate::OnDismissed() {
   DCHECK(view_);
 
   is_visible_ = false;
-
-  // Update applist button status when app list visibility is changed.
-  Shelf* shelf = Shelf::ForWindow(view_->GetWidget()->GetNativeWindow());
-  AppListButton* app_list_button = shelf->shelf_widget()->GetAppListButton();
-  if (app_list_button)
-    app_list_button->OnAppListDismissed();
+  aura::Window* root_window =
+      RootWindowController::ForTargetRootWindow()->GetRootWindow();
+  Shell::Get()->OnAppListVisibilityChanged(is_visible_, root_window);
 }
 
 void AppListPresenterDelegate::UpdateBounds() {