Enable the cups backend when --enable-native-cups is specified.

chrome/browser/chromeos/chrome_browser_main_chromeos.cc

Index: chrome/browser/chromeos/chrome_browser_main_chromeos.cc
diff --git a/chrome/browser/chromeos/chrome_browser_main_chromeos.cc b/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
index edd09d6ea51f8aeb18f75b5d437b39f97022646b..a29bfaef1816a1ec30d93f6c5bb5718d49849536 100644
--- a/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
+++ b/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
@@ -141,6 +141,7 @@
 #include "net/socket/ssl_server_socket.h"
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_context_getter.h"
+#include "printing/backend/print_backend.h"
 #include "ui/base/ime/chromeos/ime_keyboard.h"
 #include "ui/base/ime/chromeos/input_method_manager.h"
 #include "ui/base/touch/touch_device.h"
@@ -505,6 +506,10 @@ void ChromeBrowserMainPartsChromeos::PreProfileInit() {
     WizardController::SetZeroDelays();
   }
 
+  // Enable/disable native CUPS integration
+  printing::PrintBackend::SetNativeCupsEnabled(
+      parsed_command_line().HasSwitch(::switches::kEnableNativeCups));
+
   power_prefs_.reset(new PowerPrefs(PowerPolicyController::Get()));
 
   // In Aura builds this will initialize ash::Shell.