Reset user data directory and disk cache directory after downgrade.

chrome/browser/policy/policy_path_parser_win.cc

 // Copyright (c) 2011 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/browser/policy/policy_path_parser.h"
 
 #include <shlobj.h>
 #include <stddef.h>
 #include <wtsapi32.h>
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/win/registry.h"
 #include "chrome/common/chrome_switches.h"
 #include "policy/policy_constants.h"
 
 namespace {
 
 // Checks if the key exists in the given hive and expands any string variables.
-bool LoadUserDataDirPolicyFromRegistry(HKEY hive, base::FilePath* dir) {
+bool LoadUserDataDirPolicyFromRegistry(HKEY hive,
+                                       const char* key_name_str,
+                                       base::FilePath* dir) {
   base::string16 value;
-  base::string16 key_name(base::ASCIIToUTF16(policy::key::kUserDataDir));
+  base::string16 key_name(base::ASCIIToUTF16(key_name_str));
   base::win::RegKey key(hive, policy::kRegistryChromePolicyKey, KEY_READ);
   if (key.ReadValue(key_name.c_str(), &value) == ERROR_SUCCESS) {
     *dir = base::FilePath(policy::path_parser::ExpandPathVariables(value));
     return true;
   }
   return false;
 }
 
 const WCHAR* kMachineNamePolicyVarName = L"${machine_name}";
 const WCHAR* kUserNamePolicyVarName = L"${user_name}";
@@ skipping 105 matching lines @@
   // TODO(pastarmovj): Consider reorganizing this code once there are even more
   // variables to be supported. The search for the var and its replacement can
   // be extracted as common functionality.
 
   return result;
 }
 
 void CheckUserDataDirPolicy(base::FilePath* user_data_dir) {
   DCHECK(user_data_dir);
   // Policy from the HKLM hive has precedence over HKCU.
-  if (!LoadUserDataDirPolicyFromRegistry(HKEY_LOCAL_MACHINE, user_data_dir))
-    LoadUserDataDirPolicyFromRegistry(HKEY_CURRENT_USER, user_data_dir);
+  if (!LoadUserDataDirPolicyFromRegistry(HKEY_LOCAL_MACHINE, key::kUserDataDir,
+                                         user_data_dir)) {
+    LoadUserDataDirPolicyFromRegistry(HKEY_CURRENT_USER, key::kUserDataDir,
+                                      user_data_dir);
+  }
+}
+
+void CheckDiskCacheDirPolicy(base::FilePath* disk_cache_dir) {
+  DCHECK(disk_cache_dir);
+  if (!LoadUserDataDirPolicyFromRegistry(HKEY_LOCAL_MACHINE, key::kDiskCacheDir,
+                                         disk_cache_dir)) {
+    LoadUserDataDirPolicyFromRegistry(HKEY_CURRENT_USER, key::kDiskCacheDir,
+                                      disk_cache_dir);
+  }
 }
 
 }  // namespace path_parser
 
 }  // namespace policy