Remove all code related to the PreRead field trial.

chrome/app/chrome_exe_main_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 <windows.h>
 #include <malloc.h>
 #include <shellscalingapi.h>
 #include <stddef.h>
 #include <tchar.h>
 
@@ skipping 16 matching lines @@
 #include "chrome/browser/policy/policy_path_parser.h"
 #include "chrome/browser/win/chrome_process_finder.h"
 #include "chrome/common/chrome_paths_internal.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/installer/util/browser_distribution.h"
 #include "chrome_elf/chrome_elf_main.h"
 #include "components/crash/content/app/crash_switches.h"
 #include "components/crash/content/app/crashpad.h"
 #include "components/crash/content/app/run_as_crashpad_handler_win.h"
 #include "components/startup_metric_utils/browser/startup_metric_utils.h"
-#include "components/startup_metric_utils/common/pre_read_field_trial_utils_win.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/result_codes.h"
 
 namespace {
 
 // List of switches that it's safe to rendezvous early with. Fast start should
 // not be done if a command line contains a switch not in this set.
 // Note this is currently stored as a list of two because it's probably faster
 // to iterate over this small array than building a map for constant time
 // lookups.
@@ skipping 159 matching lines @@
   HINSTANCE instance = GetModuleHandle(nullptr);
 #endif
   // Initialize the CommandLine singleton from the environment.
   base::CommandLine::Init(0, nullptr);
   const base::CommandLine* command_line =
       base::CommandLine::ForCurrentProcess();
 
   const std::string process_type =
       command_line->GetSwitchValueASCII(switches::kProcessType);
 
-  startup_metric_utils::InitializePreReadOptions(
-      BrowserDistribution::GetDistribution()->GetRegistryPath());
-
   // Confirm that an explicit prefetch profile is used for all process types
   // except for the browser process. Any new process type will have to assign
   // itself a prefetch id. See kPrefetchArgument* constants in
   // content_switches.cc for details.
   DCHECK(process_type.empty() ||
          HasValidWindowsPrefetchArgument(*command_line));
 
   if (process_type == crash_reporter::switches::kCrashpadHandler) {
     return crash_reporter::RunAsCrashpadHandler(
         *base::CommandLine::ForCurrentProcess());
@@ skipping 15 matching lines @@
   RemoveAppCompatFlagsEntry();
 
   // Load and launch the chrome dll. *Everything* happens inside.
   VLOG(1) << "About to load main DLL.";
   MainDllLoader* loader = MakeMainDllLoader();
   int rc = loader->Launch(instance);
   loader->RelaunchChromeBrowserWithNewCommandLineIfNeeded();
   delete loader;
   return rc;
 }