Base: Make RegistryOverrideManager support sharded/parallel tests.

chrome/installer/setup/setup_util_unittest.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/installer/setup/setup_util_unittest.h"
 
 #include <windows.h>
 
 #include <string>
 
@@ skipping 388 matching lines @@
   base::FilePath patch_source(installer::FindArchiveToPatch(
       *original_state_, *installer_state_));
   EXPECT_EQ(base::FilePath::StringType(), patch_source.value());
 }
 
 namespace {
 
 class MigrateMultiToSingleTest : public testing::Test {
  protected:
   virtual void SetUp() OVERRIDE {
     registry_override_manager_.OverrideRegistry(kRootKey,

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

i think it's desirable to do the cleanup in TearDown rather than in the
fixture's dtor. please either make registry_override_manager_ a scoped_ptr, new
it up here, and .reset() it in TearDown; or retain something like
RemoveAllOverrides. i left a similar comment in another file.

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

I think adding a RemoveAllOverrides() method would just confuse people, since
the manager is designed to operate in a scoped-manner.

I see what you mean about the lack-of-symmetry between SetUp and TearDown
though. I was really hoping for a manager with 'scoped' semantics. It is kind of
lame that there are setup functions that need to be called for each overridden
hive.

Maybe there's a better 'third' solution.

                                                 L"MigrateMultiToSingleTest");
   }
 
-  virtual void TearDown() OVERRIDE {
-    registry_override_manager_.RemoveAllOverrides();
-  }
-
   static const bool kSystemLevel = false;
   static const HKEY kRootKey;
   static const wchar_t kVersionString[];
   static const wchar_t kMultiChannel[];
   registry_util::RegistryOverrideManager registry_override_manager_;
 };
 
 const bool MigrateMultiToSingleTest::kSystemLevel;
 const HKEY MigrateMultiToSingleTest::kRootKey =
     kSystemLevel ? HKEY_LOCAL_MACHINE : HKEY_CURRENT_USER;
@@ skipping 53 matching lines @@
                                       BrowserDistribution::CHROME_FRAME));
   EXPECT_TRUE(chrome_frame.GetUsageStats(&usagestats));
   EXPECT_EQ(1U, usagestats);
   EXPECT_EQ(L"2.0-dev", chrome_frame.channel().value());
 
   // Confirm that the binaries' channel no longer contains GCF.
   ASSERT_TRUE(binaries.Initialize(kSystemLevel,
                                   BrowserDistribution::CHROME_BINARIES));
   EXPECT_EQ(L"2.0-dev-multi", binaries.channel().value());
 }