Reset user data directory and disk cache directory after downgrade.

chrome/browser/downgrade/user_data_downgrade_browsertest.cc

Index: chrome/browser/downgrade/user_data_downgrade_browsertest.cc
diff --git a/chrome/browser/downgrade/user_data_downgrade_browsertest.cc b/chrome/browser/downgrade/user_data_downgrade_browsertest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..cb1a3241262aa21e815218c8fa7e040f5a91b64d
--- /dev/null
+++ b/chrome/browser/downgrade/user_data_downgrade_browsertest.cc
@@ -0,0 +1,123 @@
+// Copyright 2016 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/downgrade/user_data_downgrade.h"
+
+#include "base/files/file_util.h"
+#include "base/path_service.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/test/test_reg_util_win.h"
+#include "base/version.h"
+#include "base/win/registry.h"
+#include "chrome/common/chrome_constants.h"
+#include "chrome/common/chrome_paths.h"
+#include "chrome/installer/util/browser_distribution.h"
+#include "chrome/installer/util/google_update_constants.h"
+#include "chrome/test/base/in_process_browser_test.h"
+#include "content/public/browser/browser_thread.h"
+
+namespace downgrade {
+
+class UserDataDowngradeBrowserTestBase : public InProcessBrowserTest {
+ protected:
+  // content::BrowserTestBase:
+  void SetUpInProcessBrowserTestFixture() override {
+    SetSimulateDowngradeForTest(true);
+    HKEY root = HKEY_CURRENT_USER;
+    registry_override_manager_.OverrideRegistry(root);
+    key_.Create(root,
+                BrowserDistribution::GetDistribution()->GetStateKey().c_str(),
+                KEY_SET_VALUE | KEY_WOW64_32KEY);
+  }
+
+  // InProcessBrowserTest:
+  bool SetUpUserDataDirectory() override {
+    if (!PathService::Get(chrome::DIR_USER_DATA, &user_data_dir_))
+      return false;
+    if (!CreateTemporaryFileInDir(user_data_dir_, &other_file_))
+      return false;
+    last_version_file_path_ = user_data_dir_.Append(kDowngradeLastVersionFile);
+    std::string last_version = GetNextChromeVersion();
+    base::WriteFile(last_version_file_path_, last_version.c_str(),
+                    last_version.size());
+    return true;
+  }
+
+  // content::BrowserTestBase:
+  // Verify the renamed user data directory has been deleted.
+  void TearDownInProcessBrowserTestFixture() override {
+    const base::FilePath::StringType index_suffix = FILE_PATH_LITERAL(" (1)");
+    ASSERT_FALSE(base::DirectoryExists(
+        base::FilePath(user_data_dir_.value() + index_suffix)
+            .AddExtension(kDowngradeDeleteSuffix)));
+    SetSimulateDowngradeForTest(false);
+    key_.Close();
+  }
+
+  std::string GetNextChromeVersion() {
+    return base::Version(std::string(chrome::kChromeVersion) + "1").GetString();
+  }
+
+  base::FilePath last_version_file_path_;
+  // The path to an arbitrary file in the user data dir that will be present
+  // only when a reset does not take place.
+  base::FilePath other_file_;
+  base::FilePath user_data_dir_;
+  base::win::RegKey key_;
+  registry_util::RegistryOverrideManager registry_override_manager_;
+};
+
+class UserDataDowngradeBrowserCopyAndCleanTest
+    : public UserDataDowngradeBrowserTestBase {
+ protected:
+  // content::BrowserTestBase:
+  void SetUpInProcessBrowserTestFixture() override {
+    UserDataDowngradeBrowserTestBase::SetUpInProcessBrowserTestFixture();
+    key_.WriteValue(L"DowngradeVersion",
+                    base::ASCIIToUTF16(GetNextChromeVersion()).c_str());
+    key_.WriteValue(google_update::kRegMSIField, 1);
+  }
+};
+
+class UserDataDowngradeBrowserNoResetTest
+    : public UserDataDowngradeBrowserTestBase {
+ protected:
+  // content::BrowserTestBase:
+  void SetUpInProcessBrowserTestFixture() override {
+    UserDataDowngradeBrowserTestBase::SetUpInProcessBrowserTestFixture();
+    key_.WriteValue(google_update::kRegMSIField, 1);
+  }
+};
+
+class UserDataDowngradeBrowserNoMSITest
+    : public UserDataDowngradeBrowserTestBase {
+ protected:
+  // content::BrowserTestBase:
+  void SetUpInProcessBrowserTestFixture() override {
+    UserDataDowngradeBrowserTestBase::SetUpInProcessBrowserTestFixture();
+  }
+
+  // InProcessBrowserTest:
+  bool SetUpUserDataDirectory() override { return true; }
+};
+
+// Verify the user data directory has been renamed and created again after
+// downgrade.
+IN_PROC_BROWSER_TEST_F(UserDataDowngradeBrowserCopyAndCleanTest, Test) {
+  EXPECT_EQ(chrome::kChromeVersion, GetLastVersion(user_data_dir_).GetString());
+  ASSERT_FALSE(base::PathExists(other_file_));
+}
+
+// Verify the user data directory will not be reset without downgrade.
+IN_PROC_BROWSER_TEST_F(UserDataDowngradeBrowserNoResetTest, Test) {
+  EXPECT_EQ(chrome::kChromeVersion, GetLastVersion(user_data_dir_).GetString());
+  ASSERT_TRUE(base::PathExists(other_file_));
+}
+
+// Verify the "Last Version" file won't be created for non-msi install.
+IN_PROC_BROWSER_TEST_F(UserDataDowngradeBrowserNoMSITest, Test) {
+  ASSERT_FALSE(base::PathExists(last_version_file_path_));
+}
+
+}  // namespace downgrade