Remove all code related to the PreRead field trial.

chrome/app/main_dll_loader_win.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/app/main_dll_loader_win.h"
 
 #include <windows.h>  // NOLINT
 #include <shlwapi.h>  // NOLINT
 #include <stddef.h>
 #include <userenv.h>  // NOLINT
@@ skipping 24 matching lines @@
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/chrome_result_codes.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/metrics_constants_util_win.h"
 #include "chrome/installer/util/google_update_constants.h"
 #include "chrome/installer/util/google_update_settings.h"
 #include "chrome/installer/util/install_util.h"
 #include "chrome/installer/util/module_util_win.h"
 #include "chrome/installer/util/util_constants.h"
-#include "components/startup_metric_utils/common/pre_read_field_trial_utils_win.h"
 #include "content/public/app/sandbox_helper_win.h"
 #include "content/public/common/content_switches.h"
 #include "sandbox/win/src/sandbox.h"
 
 namespace {
 // The entry point signature of chrome.dll.
 typedef int (*DLL_MAIN)(HINSTANCE, sandbox::SandboxInterfaceInfo*);
 
 typedef void (*RelaunchChromeBrowserWithNewCommandLineIfNeededFunc)();
 
 // Loads |module| after setting the CWD to |module|'s directory. Returns a
 // reference to the loaded module on success, or null on error.
 HMODULE LoadModuleWithDirectory(const base::FilePath& module) {
   ::SetCurrentDirectoryW(module.DirName().value().c_str());
-
-  const startup_metric_utils::PreReadOptions pre_read_options =
-      startup_metric_utils::GetPreReadOptions();
-
-  // If enabled by the PreRead field trial, pre-read the binary to avoid a lot
-  // of random IO.
-  if (pre_read_options.pre_read)
-    PreReadFile(module, pre_read_options);
-
+  PreReadFile(module);
   return ::LoadLibraryExW(module.value().c_str(), nullptr,
                           LOAD_WITH_ALTERED_SEARCH_PATH);
 }
 
 void RecordDidRun(const base::FilePath& dll_path) {
   bool system_level = !InstallUtil::IsPerUserInstall(dll_path);
   GoogleUpdateSettings::UpdateDidRunState(true, system_level);
 }
 
 void ClearDidRun(const base::FilePath& dll_path) {
@@ skipping 168 matching lines @@
   }
 };
 
 MainDllLoader* MakeMainDllLoader() {
 #if defined(GOOGLE_CHROME_BUILD)
   return new ChromeDllLoader();
 #else
   return new ChromiumDllLoader();
 #endif
 }