Reset user data directory and disk cache directory after downgrade.

chrome/browser/chrome_browser_main.cc

Index: chrome/browser/chrome_browser_main.cc
diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index 9d8554f5a6656fe1776b73b0e8d2ff03905a6c12..b5c18dee871f8c8e84dc0ddfe23f5a8b746754dd 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -202,6 +202,7 @@
 #include "chrome/browser/chrome_select_file_dialog_factory_win.h"
 #include "chrome/browser/component_updater/caps_installer_win.h"
 #include "chrome/browser/component_updater/sw_reporter_installer_win.h"
+#include "chrome/browser/downgrade/user_data_downgrade.h"
 #include "chrome/browser/first_run/try_chrome_dialog_view.h"
 #include "chrome/browser/first_run/upgrade_util_win.h"
 #include "chrome/browser/metrics/chrome_metrics_service_accessor.h"
@@ -1776,6 +1777,11 @@ int ChromeBrowserMainParts::PreMainMessageLoopRunImpl() {
       g_browser_process->profile_manager()->GetLastOpenedProfiles();
 #endif  // defined(OS_CHROMEOS)
 
+#if defined(OS_WIN)
+  // Clean up old user data directory and disk cache directory.
+  downgrade::DeleteMovedUserDataSoon();
+#endif
+
   UMA_HISTOGRAM_TIMES("Startup.PreMainMessageLoopRunImplStep2Time",
                       base::TimeTicks::Now() - start_time_step2);