Handle app custom icon via aura::Window property.

chrome/browser/ui/ash/launcher/arc_app_window_launcher_item_controller.h

Index: chrome/browser/ui/ash/launcher/arc_app_window_launcher_item_controller.h
diff --git a/chrome/browser/ui/ash/launcher/arc_app_window_launcher_item_controller.h b/chrome/browser/ui/ash/launcher/arc_app_window_launcher_item_controller.h
index ec8af9cf38c1c1f131a901588936529bee45e4cc..3ea97b2bc7debbf6eecad99a73c22124ef47210a 100644
--- a/chrome/browser/ui/ash/launcher/arc_app_window_launcher_item_controller.h
+++ b/chrome/browser/ui/ash/launcher/arc_app_window_launcher_item_controller.h
@@ -12,14 +12,12 @@
 #include "chrome/browser/ui/ash/launcher/app_window_launcher_item_controller.h"
 
 class ArcAppWindow;
-class ChromeLauncherController;
 
 // Shelf item delegate for ARC app windows.
 class ArcAppWindowLauncherItemController
     : public AppWindowLauncherItemController {
  public:
-  ArcAppWindowLauncherItemController(const std::string& arc_app_id,
-                                     ChromeLauncherController* owner);
+  explicit ArcAppWindowLauncherItemController(const std::string& arc_app_id);
 
   ~ArcAppWindowLauncherItemController() override;
 
@@ -35,18 +33,12 @@ class ArcAppWindowLauncherItemController
   void RemoveTaskId(int task_id);
   bool HasAnyTasks() const;
 
-  // AppWindowLauncherItemController:
-  void UpdateLauncherItem() override;
-
  private:
   // Update the shelf item's icon for the active window.
   void UpdateIcon(ArcAppWindow* arc_app_window);
 
   std::unordered_set<int> task_ids_;
 
-  // Unowned property.
-  ChromeLauncherController* const owner_;
-
   DISALLOW_COPY_AND_ASSIGN(ArcAppWindowLauncherItemController);
 };