Handle app custom icon via aura::Window property.

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

Index: chrome/browser/ui/ash/launcher/app_window_launcher_item_controller.h
diff --git a/chrome/browser/ui/ash/launcher/app_window_launcher_item_controller.h b/chrome/browser/ui/ash/launcher/app_window_launcher_item_controller.h
index e1fd8767a114e4be4af3debd6ca8c8b24f7e9e4c..d8de87ebcea44fb554399789047b5399a3c76107 100644
--- a/chrome/browser/ui/ash/launcher/app_window_launcher_item_controller.h
+++ b/chrome/browser/ui/ash/launcher/app_window_launcher_item_controller.h
@@ -13,6 +13,8 @@
 #include "base/scoped_observer.h"
 #include "ui/aura/window_observer.h"
 
+class ChromeLauncherController;
+
 namespace aura {
 class Window;
 }
@@ -60,15 +62,11 @@ class AppWindowLauncherItemController : public ash::ShelfItemDelegate,
   // Activates the window at position |index|.
   void ActivateIndexedApp(size_t index);
 
-  // Called when launcher item may need to be updated, eg. label or icon.
-  // TODO(khmel): Use aura::Window property and observe property change
-  // http://crbug.com/724292
-  virtual void UpdateLauncherItem() {}
-
   const WindowList& windows() const { return windows_; }
 
  protected:
-  explicit AppWindowLauncherItemController(const ash::ShelfID& shelf_id);
+  AppWindowLauncherItemController(const ash::ShelfID& shelf_id,
+                                  ChromeLauncherController* owner);
 
   // Returns the action performed. Should be one of SHELF_ACTION_NONE,
   // SHELF_ACTION_WINDOW_ACTIVATED, or SHELF_ACTION_WINDOW_MINIMIZED.
@@ -84,9 +82,16 @@ class AppWindowLauncherItemController : public ash::ShelfItemDelegate,
   // Returns last active window in the controller or first window.
   ui::BaseWindow* GetLastActiveWindow();
 
+  ChromeLauncherController* owner() { return owner_; }
+
  private:
   WindowList::iterator GetFromNativeWindow(aura::Window* window);
 
+  void UpdateLauncherItem();

[msw, 2017/05/23 00:02:29]

nit: comment (or inline in OnWindowPropertyChanged), rename UpdateShelfItemIcon?

[khmel, 2017/05/23 16:11:43]

Done. Inlining is not very possible because it is called not only on prop change
but also when active window is changed (case multiple windows in one
controller).

+
+  // Unowned pointer.
+  ChromeLauncherController* const owner_;
+
   // List of associated app windows
   WindowList windows_;