Reset user data directory and disk cache directory after downgrade.

chrome/app/chrome_main_delegate.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/app/chrome_main_delegate.h"
 
 #include <stddef.h>
 #include <string>
 
 #include "base/base_paths.h"
@@ skipping 42 matching lines @@
 #include "extensions/common/constants.h"
 #include "ui/base/material_design/material_design_controller.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_switches.h"
 
 #if defined(OS_WIN)
 #include <atlbase.h>
 #include <malloc.h>
 #include <algorithm>
 #include "base/debug/close_handle_hook_win.h"
+#include "chrome/browser/downgrade/user_data_downgrade.h"
 #include "chrome/common/child_process_logging.h"
 #include "chrome/common/v8_breakpad_support_win.h"
 #include "components/crash/content/app/crashpad.h"
 #include "sandbox/win/src/sandbox.h"
 #include "ui/base/resource/resource_bundle_win.h"
 #endif
 
 #if defined(OS_MACOSX)
 #include "base/mac/foundation_util.h"
 #include "chrome/app/chrome_main_mac.h"
@@ skipping 652 matching lines @@
 #if defined(OS_WIN)
   child_process_logging::Init();
 #endif
 #if defined(ARCH_CPU_ARM_FAMILY) && (defined(OS_ANDROID) || defined(OS_LINUX))
   // Create an instance of the CPU class to parse /proc/cpuinfo and cache
   // cpu_brand info.
   base::CPU cpu_info;
 #endif
 
   // Initialize the user data dir for any process type that needs it.
-  if (chrome::ProcessNeedsProfileDir(process_type))
+  if (chrome::ProcessNeedsProfileDir(process_type)) {
     InitializeUserDataDir();
+#if defined(OS_WIN) && !defined(CHROME_MULTIPLE_DLL_CHILD)
+    if (downgrade::IsMSIInstall()) {
+      downgrade::MoveUserDataForFirstRunAfterDowngrade();
+      base::FilePath user_data_dir;
+      if (PathService::Get(chrome::DIR_USER_DATA, &user_data_dir))
+        downgrade::UpdateLastVersion(user_data_dir);
+    }
+#endif
+  }
 
   // Register component_updater PathProvider after DIR_USER_DATA overidden by
   // command line flags. Maybe move the chrome PathProvider down here also?
   component_updater::RegisterPathProvider(chrome::DIR_COMPONENTS,
                                           chrome::DIR_USER_DATA);
 
   // Enable Message Loop related state asap.
   if (command_line.HasSwitch(switches::kMessageLoopHistogrammer))
     base::MessageLoop::EnableHistogrammer(true);
 
@@ skipping 286 matching lines @@
     case version_info::Channel::CANARY:
       return true;
     case version_info::Channel::DEV:
     case version_info::Channel::BETA:
     case version_info::Channel::STABLE:
     default:
       // Don't enable instrumentation.
       return false;
   }
 }