Let the incognito window print.

chrome/browser/chromeos/printing/printer_pref_manager_factory.cc

Index: chrome/browser/chromeos/printing/printer_pref_manager_factory.cc
diff --git a/chrome/browser/chromeos/printing/printer_pref_manager_factory.cc b/chrome/browser/chromeos/printing/printer_pref_manager_factory.cc
index e70ef4f4eb0a206ad1ba030af74b5259d689aa86..4f082568fd3ece4c71b3ffdd568682ae72577845 100644
--- a/chrome/browser/chromeos/printing/printer_pref_manager_factory.cc
+++ b/chrome/browser/chromeos/printing/printer_pref_manager_factory.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/chromeos/printing/printer_pref_manager_factory.h"
 
+#include "chrome/browser/profiles/incognito_helpers.h"
 #include "chrome/browser/profiles/profile.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "content/public/browser/browser_context.h"
@@ -30,6 +31,11 @@ PrinterPrefManagerFactory* PrinterPrefManagerFactory::GetInstance() {
   return g_printer_pref_manager.Pointer();
 }
 
+content::BrowserContext* PrinterPrefManagerFactory::GetBrowserContextToUse(
+    content::BrowserContext* context) const {
+  return chrome::GetBrowserContextRedirectedInIncognito(context);
+}
+
 PrinterPrefManagerFactory::PrinterPrefManagerFactory()
     : BrowserContextKeyedServiceFactory(
           "PrinterPrefManager",