Use valid /prefetch arguments for process launches on Windows. - do not submit

components/startup_metric_utils/common/pre_read_field_trial_utils_win.h

 // Copyright 2015 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.
 
 #ifndef COMPONENTS_STARTUP_METRIC_UTILS_COMMON_PRE_READ_FIELD_TRIAL_UTILS_WIN_H_
 #define COMPONENTS_STARTUP_METRIC_UTILS_COMMON_PRE_READ_FIELD_TRIAL_UTILS_WIN_H_
 
 #include <string>
 
 #include "base/callback_forward.h"
 #include "base/strings/string16.h"
 
 // Utility functions to support the PreRead field trial. The PreRead field trial
 // changes the way DLLs are pre-read during startup.
 
 namespace startup_metric_utils {
 
 // Callback to register a synthetic field trial.
 using RegisterPreReadSyntheticFieldTrialCallback =
     const base::Callback<bool(const std::string&, const std::string&)>;
 
 // Get DLL pre-reading options. |product_registry_path| is the registry path
 // under which the registry key for this field trial resides. The |no_pre_read|
 // option is set if DLLs should not be pre-read. The |high_priority| option is
 // set if pre-reading should be done with a high thread priority. The
 // |only_if_cold| option is set if only cold DLLs should be pre-read. The
 // |prefetch_virtual_memory| option is set if the
 // ::PrefetchVirtualMemory function should be used to pre-read DLLs, if
-// available.
+// available. The |prefetch_argument| option is set if a prefetch argument
+// should be specified when launching a process.
 void GetPreReadOptions(const base::string16& product_registry_path,
                        bool* no_pre_read,
                        bool* high_priority,
                        bool* only_if_cold,
-                       bool* prefetch_virtual_memory);
+                       bool* prefetch_virtual_memory,
+                       bool* prefetch_argument);

[gab, 2016/01/18 19:10:52]

As suggested in caller above I'd say let's do:

enum PreReadOptions {
  NO_PRE_READ = 1 << 0,
  HIGH_PRIORITY = 1 << 1,
  ONLY_IF_COLD = 1 << 2,
  PREFETCH_VIRTUAL_MEMORY = 1 << 3,
  PREFETCH_ARGUMENT = 1 << 4,
}

int GetPreReadOptions(const base::string16& product_registry_path);
  

+comments

 
 // Updates DLL pre-reading options in the registry with the latest info for the
 // next startup. |product_registry_path| is the registry path under which the
 // registry key for this field trial resides.
 void UpdatePreReadOptions(const base::string16& product_registry_path);
 
 // Registers a synthetic field trial with the PreRead group currently stored in
 // the registry. This must be done before the first metric log
 // (metrics::MetricsLog) is created. Otherwise, UMA metrics generated during
 // startup won't be correctly annotated. |product_registry_path| is the registry
 // path under which the key for this field trial resides.
 void RegisterPreReadSyntheticFieldTrial(
     const base::string16& product_registry_path,
     const RegisterPreReadSyntheticFieldTrialCallback&
         register_synthetic_field_trial);
 
 }  // namespace startup_metric_utils
 
 #endif  // COMPONENTS_STARTUP_METRIC_UTILS_COMMON_PRE_READ_FIELD_TRIAL_UTILS_WIN_H_