Move enable_app_list to a buildflag.

chrome/browser/ui/startup/startup_browser_creator.cc

Index: chrome/browser/ui/startup/startup_browser_creator.cc
diff --git a/chrome/browser/ui/startup/startup_browser_creator.cc b/chrome/browser/ui/startup/startup_browser_creator.cc
index 227687563226fea409ecea1d6d4c808b90ce04bb..d46bb4f49354c3fc334eea77030862e950fc157e 100644
--- a/chrome/browser/ui/startup/startup_browser_creator.cc
+++ b/chrome/browser/ui/startup/startup_browser_creator.cc
@@ -61,6 +61,7 @@
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_result_codes.h"
 #include "chrome/common/chrome_switches.h"
+#include "chrome/common/features.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/installer/util/browser_distribution.h"
@@ -109,7 +110,7 @@
 #include "chrome/browser/printing/print_dialog_cloud.h"
 #endif
 
-#if defined(ENABLE_APP_LIST)
+#if BUILDFLAG(ENABLE_APP_LIST)
 #include "chrome/browser/ui/app_list/app_list_service.h"
 #endif
 
@@ -871,7 +872,7 @@ base::FilePath GetStartupProfilePath(const base::FilePath& user_data_dir,
         command_line.GetSwitchValuePath(switches::kProfileDirectory));
   }
 
-#if defined(ENABLE_APP_LIST)
+#if BUILDFLAG(ENABLE_APP_LIST)
   // If we are showing the app list then chrome isn't shown so load the app
   // list's profile rather than chrome's.
   if (command_line.HasSwitch(switches::kShowAppList))