Remove code that deletes the PreReadFieldTrial registry key.

chrome/browser/chrome_browser_main.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/browser/chrome_browser_main.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <set>
@@ skipping 182 matching lines @@
 #include "chromeos/settings/cros_settings_names.h"
 #endif  // defined(OS_CHROMEOS)
 
 // TODO(port): several win-only methods have been pulled out of this, but
 // BrowserMain() as a whole needs to be broken apart so that it's usable by
 // other platforms. For now, it's just a stub. This is a serious work in
 // progress and should not be taken as an indication of a real refactoring.
 
 #if defined(OS_WIN)
 #include "base/trace_event/trace_event_etw_export_win.h"
-#include "base/win/registry.h"
 #include "base/win/win_util.h"
 #include "chrome/browser/chrome_browser_main_win.h"
 #include "chrome/browser/component_updater/sw_reporter_installer_win.h"
 #include "chrome/browser/downgrade/user_data_downgrade.h"
 #include "chrome/browser/first_run/upgrade_util_win.h"
 #include "chrome/browser/ui/network_profile_bubble.h"
 #include "chrome/browser/ui/views/try_chrome_dialog_view.h"
 #include "chrome/browser/win/browser_util.h"
 #include "chrome/browser/win/chrome_select_file_dialog_factory.h"
 #include "chrome/install_static/install_util.h"
@@ skipping 544 matching lines @@
   // for posting tasks via base::Bind. Its deleted when it goes out of scope.
   // Even though base::Bind does AddRef and Release, the object will not be
   // deleted after the Task is executed.
   field_trial_synchronizer_ = new FieldTrialSynchronizer();
 
 #if defined(OS_WIN) || defined(OS_MACOSX) || \
     (defined(OS_LINUX) && !defined(OS_CHROMEOS))
   metrics::DesktopSessionDurationTracker::Initialize();
 #endif
   metrics::RendererUptimeTracker::Initialize();
-
-#if defined(OS_WIN)
-  // Cleanup the PreRead field trial registry key.
-  // TODO(fdoray): Remove this when M56 hits stable.
-  const base::string16 pre_read_field_trial_registry_path =
-      install_static::GetRegistryPath() + L"\\PreReadFieldTrial";
-  base::win::RegKey(HKEY_CURRENT_USER,
-                    pre_read_field_trial_registry_path.c_str(), KEY_SET_VALUE)
-      .DeleteKey(L"");
-#endif  // defined(OS_WIN)
 }
 
 void ChromeBrowserMainParts::SetupMetrics() {
   TRACE_EVENT0("startup", "ChromeBrowserMainParts::SetupMetrics");
   metrics::MetricsService* metrics = browser_process_->metrics_service();
   metrics->AddSyntheticTrialObserver(
       variations::VariationsHttpHeaderProvider::GetInstance());
   // Now that field trials have been created, initializes metrics recording.
   metrics->InitializeMetricsRecordingState();
 
@@ skipping 1288 matching lines @@
   chromeos::CrosSettings::Shutdown();
 #endif  // defined(OS_CHROMEOS)
 #endif  // defined(OS_ANDROID)
 }
 
 // Public members:
 
 void ChromeBrowserMainParts::AddParts(ChromeBrowserMainExtraParts* parts) {
   chrome_extra_parts_.push_back(parts);
 }