Move pre_read_field_trial_utils.h/cc to common/.

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_FILE_PRE_READ_FIELD_TRIAL_UTILS_WIN_H_
-#define COMPONENTS_STARTUP_METRIC_UTILS_FILE_PRE_READ_FIELD_TRIAL_UTILS_WIN_H_
+#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 {
@@ skipping 26 matching lines @@
 // (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_FILE_PRE_READ_FIELD_TRIAL_UTILS_WIN_H_
+#endif  // COMPONENTS_STARTUP_METRIC_UTILS_COMMON_PRE_READ_FIELD_TRIAL_UTILS_WIN_H_