Discard pinning an app with non-empty launcher id.

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

Index: chrome/browser/ui/ash/launcher/chrome_launcher_controller_mus.cc
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_controller_mus.cc b/chrome/browser/ui/ash/launcher/chrome_launcher_controller_mus.cc
index e51e737c3f95dbfa094af909b744ddaf9b15db09..3293679bcfcda9c3e0fce01ae768a53e8d900f23 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_controller_mus.cc
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_controller_mus.cc
@@ -8,6 +8,7 @@
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/browser/ui/ash/app_launcher_id.h"
 #include "chrome/browser/ui/ash/chrome_launcher_prefs.h"
 #include "chrome/browser/ui/ash/launcher/launcher_controller_helper.h"
 #include "extensions/grit/extensions_browser_resources.h"
@@ -279,7 +280,7 @@ void ChromeLauncherControllerMus::PinAppsFromPrefs() {
 
   for (const auto& app_launcher_id : pinned_apps) {
     const std::string app_id = app_launcher_id.app_id();
-    if (app_launcher_id.ToString() == ash::launcher::kPinnedAppsPlaceholder)
+    if (app_launcher_id.app_id() == ash::launcher::kPinnedAppsPlaceholder)
       continue;
 
     ash::mojom::ShelfItemPtr item(ash::mojom::ShelfItem::New());