Draggable peeking/fullscreen launcher with transparent background.

ash/app_list/app_list_delegate_impl.cc

Index: ash/app_list/app_list_delegate_impl.cc
diff --git a/ash/app_list/app_list_delegate_impl.cc b/ash/app_list/app_list_delegate_impl.cc
index c8fbf0f0edde5c4af59d8358fb5f6e6c17f0016b..3c51896a1ceffd604bc7022350eee6a9bfc04874 100644
--- a/ash/app_list/app_list_delegate_impl.cc
+++ b/ash/app_list/app_list_delegate_impl.cc
@@ -11,6 +11,7 @@
 #include "ash/shell.h"
 #include "ash/shell_port.h"
 #include "ash/wm_window.h"
+#include "ui/app_list/app_list_features.h"
 #include "ui/app_list/presenter/app_list.h"
 
 namespace ash {
@@ -36,6 +37,11 @@ void AppListDelegateImpl::OnAppListVisibilityChanged(bool visible,
     app_list_button->OnAppListShown();
   else
     app_list_button->OnAppListDismissed();
+
+  if (app_list::features::IsFullscreenAppListEnabled()) {
+    Shelf* shelf = Shelf::ForWindow(root_window);
+    shelf->OnAppListIsActive(visible);

[xiyuan, 2017/05/30 22:18:50]

nit: get rid of |shelf| and use Shelf::ForWindow in-place

i.e.
  Shelf::ForWindow(root_window)->OnAppListIsActive(visible);

and if it could fit in one line, get rid of {} as well.

[newcomer, 2017/06/01 01:42:53]

Done.

[sky, 2017/06/01 13:34:05]

Thanks for starting down this path! What I'm really suggesting here is Shell
becomes the ApplistDelegate. Shell::OnApplistVisibilityChanged() *always* calls
to OnAppListIsActive, or at this point we should name it
OnAppListVisibilityChanged(). Shelf code has a ShellObserver that updates both
the app-list_button and whatever you need the new code to do? In other words,
I'm suggesting you nuke this class entirely.

[newcomer, 2017/06/05 22:01:44]

Discussed Offline, I've created a bug and plan merge the change into a new CL.

+  }
 }
 
 }  // namespace ash