Base: Make RegistryOverrideManager support sharded/parallel tests.

chrome/installer/util/product_state_unittest.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 <windows.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"
@@ skipping 52 matching lines @@
   testing::Test::TearDownTestCase();
 }
 
 void ProductStateTest::SetUp() {
   testing::Test::SetUp();
 
   // Create/open the keys for the product we'll test.
   system_install_ = true;
   overridden_ = (system_install_ ? HKEY_LOCAL_MACHINE : HKEY_CURRENT_USER);
 
   // Override for test purposes.  We don't use ScopedRegistryKeyOverride

[grt (UTC plus 2), 2013/11/07 02:39:33]

Can RegistryOverrideManager replace this? As it is, this test looks like it
can't be parallelized.

[tommycli, 2013/11/07 18:02:07]

Done.

   // directly because it doesn't suit itself to our use here.
   RegKey temp_key;
   EXPECT_EQ(ERROR_SUCCESS,
             temp_key.Create(HKEY_CURRENT_USER, temp_key_path_.c_str(),
                             KEY_ALL_ACCESS));
   EXPECT_EQ(ERROR_SUCCESS,
             ::RegOverridePredefKey(overridden_, temp_key.Handle()));
 
   EXPECT_EQ(ERROR_SUCCESS,
             clients_.Create(overridden_, dist_->GetVersionKey().c_str(),
                             KEY_ALL_ACCESS));
   EXPECT_EQ(ERROR_SUCCESS,
             client_state_.Create(overridden_, dist_->GetStateKey().c_str(),
                                  KEY_ALL_ACCESS));
 }
 
 void ProductStateTest::TearDown() {
   // Done with the keys.
   client_state_.Close();
   clients_.Close();
   EXPECT_EQ(ERROR_SUCCESS, ::RegOverridePredefKey(overridden_, NULL));
   overridden_ = NULL;
   system_install_ = false;
 
-  // Shotgun approach to clearing out data we may have written.
-  RegistryOverrideManager::DeleteAllTempKeys();
-
   testing::Test::TearDown();
 }
 
 void ProductStateTest::MinimallyInstallProduct(const wchar_t* version) {
   EXPECT_EQ(ERROR_SUCCESS,
             clients_.WriteValue(google_update::kRegVersionField, version));
 }
 
 void ProductStateTest::ApplyUninstallCommand(const wchar_t* exe_path,
                                              const wchar_t* args) {
@@ skipping 308 matching lines @@
 
   // Uninstall command with --multi-install is multi install.
   {
     ProductState state;
     ApplyUninstallCommand(L"setup.exe",
                           L"--uninstall --chrome --multi-install");
     EXPECT_TRUE(state.Initialize(system_install_, dist_));
     EXPECT_TRUE(state.is_multi_install());
   }
 }