Handle app custom icon via aura::Window property.

chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc

Index: chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc b/chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc
index 8bbc8df797f0d402386f096c4c187d93a47ed680..ca6074b43961d7b710221c85a3df2028d5bd528d 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc
@@ -421,6 +421,7 @@ void ChromeLauncherController::ActivateApp(const std::string& app_id,
 void ChromeLauncherController::SetLauncherItemImage(
     const ash::ShelfID& shelf_id,
     const gfx::ImageSkia& image) {
+  DCHECK(!image.isNull());
   const ash::ShelfItem* item = GetItem(shelf_id);
   if (item) {
     ash::ShelfItem new_item = *item;
@@ -429,6 +430,12 @@ void ChromeLauncherController::SetLauncherItemImage(
   }
 }
 
+void ChromeLauncherController::UpdateAppItemImage(const std::string& app_id) {
+  AppIconLoader* icon_loader = GetAppIconLoaderForApp(app_id);
+  if (icon_loader)
+    icon_loader->UpdateImage(app_id);
+}
+
 void ChromeLauncherController::UpdateAppState(content::WebContents* contents,
                                               AppState app_state) {
   ash::ShelfID shelf_id(launcher_controller_helper_->GetAppID(contents));