Draggable peeking/fullscreen launcher with transparent background.

ash/shelf/shelf_layout_manager.h

Index: ash/shelf/shelf_layout_manager.h
diff --git a/ash/shelf/shelf_layout_manager.h b/ash/shelf/shelf_layout_manager.h
index 1bce22e640a5ad45401052d5bc180137ac5d6a06..d02cf2650b577acbb9f81075e5f8a7ea84dda320 100644
--- a/ash/shelf/shelf_layout_manager.h
+++ b/ash/shelf/shelf_layout_manager.h
@@ -60,11 +60,13 @@ class ASH_EXPORT ShelfLayoutManager
   ShelfLayoutManager(ShelfWidget* shelf_widget, Shelf* shelf);
   ~ShelfLayoutManager() override;
 
+  // Called when the AppList is active.

[vadimt, 2017/05/30 23:52:08]

Same

[newcomer, 2017/06/01 01:42:54]

Done.

+  void OnAppListIsActive(bool is_active);
+
   bool updating_bounds() const { return updating_bounds_; }
 
   // Clears internal data for shutdown process.
   void PrepareForShutdown();
-
   // Returns whether the shelf and its contents (shelf, status) are visible
   // on the screen.
   bool IsVisible() const;
@@ -313,6 +315,9 @@ class ASH_EXPORT ShelfLayoutManager
   // Do any windows overlap the shelf? This is maintained by WorkspaceManager.
   bool window_overlaps_shelf_;
 
+  // Wether the app list is active. Use the transparent
+  // shelf background when the flag is set to prevent overlap.
+  bool app_list_is_active_ = false;
   base::OneShotTimer auto_hide_timer_;
 
   // Whether the mouse was over the shelf when the auto hide timer started.