Fix experimental app list's start page logo not showing in Guest Mode.

chrome/browser/ui/app_list/start_page_service_factory.cc

Index: chrome/browser/ui/app_list/start_page_service_factory.cc
diff --git a/chrome/browser/ui/app_list/start_page_service_factory.cc b/chrome/browser/ui/app_list/start_page_service_factory.cc
index 95c1081e5d526300833de92358ac750d43cbc853..0e7c33f5fb03e48f6f7f88b161073946a8c35ad0 100644
--- a/chrome/browser/ui/app_list/start_page_service_factory.cc
+++ b/chrome/browser/ui/app_list/start_page_service_factory.cc
@@ -6,6 +6,7 @@
 
 #include "base/command_line.h"
 #include "chrome/browser/extensions/install_tracker_factory.h"
+#include "chrome/browser/profiles/incognito_helpers.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/app_list/start_page_service.h"
 #include "chrome/common/chrome_switches.h"
@@ -49,4 +50,10 @@ KeyedService* StartPageServiceFactory::BuildServiceInstanceFor(
   return new StartPageService(profile);
 }
 
+content::BrowserContext* StartPageServiceFactory::GetBrowserContextToUse(
+    content::BrowserContext* context) const {
+  // The start page service needs an instance in ChromeOS guest mode.
+  return chrome::GetBrowserContextRedirectedInIncognito(context);
+}
+
 }  // namespace app_list