Put the pop-up app launcher behind a compile-time flag, and provide defines.

chrome/browser/ui/startup/startup_browser_creator_impl.cc

Index: chrome/browser/ui/startup/startup_browser_creator_impl.cc
diff --git a/chrome/browser/ui/startup/startup_browser_creator_impl.cc b/chrome/browser/ui/startup/startup_browser_creator_impl.cc
index 9a7a9933491519c7ed899338e488593567781c3a..4c214c1e799359ae870b87e3c3e65f4a9584dd44 100644
--- a/chrome/browser/ui/startup/startup_browser_creator_impl.cc
+++ b/chrome/browser/ui/startup/startup_browser_creator_impl.cc
@@ -51,7 +51,6 @@
 #include "chrome/browser/sessions/session_service.h"
 #include "chrome/browser/sessions/session_service_factory.h"
 #include "chrome/browser/shell_integration.h"
-#include "chrome/browser/ui/app_list/app_list_controller.h"
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/browser_list.h"
@@ -114,6 +113,10 @@
 #include "base/win/windows_version.h"
 #endif
 
+#if defined(ENABLE_APP_LIST)
+#include "chrome/browser/ui/app_list/app_list_controller.h"
+#endif
+
 using content::ChildProcessSecurityPolicy;
 using content::WebContents;
 using extensions::Extension;
@@ -362,11 +365,13 @@ bool StartupBrowserCreatorImpl::Launch(Profile* profile,
     }
   }
 
+#if defined(ENABLE_APP_LIST)
   app_list_controller::CheckAppListTaskbarShortcut();
   if (command_line_.HasSwitch(switches::kShowAppList)) {
     app_list_controller::ShowAppList();
     return true;
   }
+#endif
 
   // Open the required browser windows and tabs. First, see if
   // we're being run as an application window. If so, the user