mash: Support ShelfModel access in Chrome.

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

Index: chrome/browser/ui/ash/launcher/chrome_launcher_controller_browsertest.cc
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_controller_browsertest.cc b/chrome/browser/ui/ash/launcher/chrome_launcher_controller_browsertest.cc
index 2f4fc9a9823c578403dae293ccdd580bc970212d..a8da6c1fda265f08174cab31e68a9b11f28f4cc2 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_controller_browsertest.cc
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_controller_browsertest.cc
@@ -2408,3 +2408,14 @@ IN_PROC_BROWSER_TEST_F(ShelfAppBrowserTest,
   ASSERT_FALSE(
       IsItemPresentInMenu(menu2.get(), LauncherContextMenu::MENU_CLOSE));
 }
+
+// Ensure Ash and Chrome ShelfModel changes are synchronized correctly.
+IN_PROC_BROWSER_TEST_F(ShelfAppBrowserTest, ShelfModelSyncsWithAsh) {
+  // The ChromeLauncherController instance should be initialized and contain
+  // shelf items for the AppList and browser shortcut.
+  ash::ShelfModel* model = controller_->shelf_model();
+  EXPECT_EQ(2, model->item_count());
+  constexpr char kAppListId[] = "jlfapfmkapbjlfbpjedlinehodkccjee";
+  EXPECT_EQ(kAppListId, model->items()[0].id.app_id);
+  EXPECT_EQ(extension_misc::kChromeAppId, model->items()[1].id.app_id);
+}