[arc-intents] Properly qualify API-generated page transitions.

ash/mus/shell_delegate_mus.h

Index: ash/mus/shell_delegate_mus.h
diff --git a/ash/mus/shell_delegate_mus.h b/ash/mus/shell_delegate_mus.h
index aa1c8d0faf98fd19319ada211f8d2da2bda554a9..bd1cfc963c9f19cead64aa2fa96ed8ff024cb6e2 100644
--- a/ash/mus/shell_delegate_mus.h
+++ b/ash/mus/shell_delegate_mus.h
@@ -37,7 +37,7 @@ class ShellDelegateMus : public ShellDelegate {
   void PreShutdown() override;
   void Exit() override;
   keyboard::KeyboardUI* CreateKeyboardUI() override;
-  void OpenUrl(const GURL& url) override;
+  void OpenUrlFromArc(const GURL& url) override;
   app_list::AppListPresenter* GetAppListPresenter() override;
   ShelfDelegate* CreateShelfDelegate(ShelfModel* model) override;
   SystemTrayDelegate* CreateSystemTrayDelegate() override;