Use a valid /prefetch argument when launching a process.

components/startup_metric_utils/common/pre_read_field_trial_utils_win.cc

 // 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.
 
 #include "components/startup_metric_utils/common/pre_read_field_trial_utils_win.h"
 
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/field_trial.h"
 #include "base/strings/string_util.h"
@@ skipping 13 matching lines @@
 // registered so that UMA metrics recorded during the current startup are
 // annotated with the pre-read group that is actually used during this startup.
 const char kPreReadSyntheticFieldTrialName[] = "SyntheticPreRead";
 
 // Variation names for the PreRead field trial.
 const base::char16 kNoPreReadVariationName[] = L"NoPreRead";
 const base::char16 kHighPriorityVariationName[] = L"HighPriority";
 const base::char16 kOnlyIfColdVariationName[] = L"OnlyIfCold";
 const base::char16 kPrefetchVirtualMemoryVariationName[] =
     L"PrefetchVirtualMemory";
+const base::char16 kNoPrefetchArgumentVariationName[] = L"NoPrefetchArgument";
 
 // Registry key in which the PreRead field trial group is stored.
 const base::char16 kPreReadFieldTrialRegistryKey[] = L"\\PreReadFieldTrial";
 
 // Pre-read options to use for the current process. This is initialized by
 // InitializePreReadOptions().
 int g_pre_read_options = PRE_READ_OPTION_UNINITIALIZED;
 
 // Returns the registry path in which the PreRead group is stored.
 base::string16 GetPreReadRegistryPath(
@@ skipping 18 matching lines @@
   // Set the PreRead field trial's options.
   struct VariationMapping {
     const base::char16* name;
     PreReadOptions bit;
   } const variations_mappings[] = {
       {kNoPreReadVariationName, PRE_READ_OPTION_NO_PRE_READ},
       {kHighPriorityVariationName, PRE_READ_OPTION_HIGH_PRIORITY},
       {kOnlyIfColdVariationName, PRE_READ_OPTION_ONLY_IF_COLD},
       {kPrefetchVirtualMemoryVariationName,
        PRE_READ_OPTION_PREFETCH_VIRTUAL_MEMORY},
+      {kNoPrefetchArgumentVariationName, PRE_READ_OPTION_NO_PREFETCH_ARGUMENT},
   };
 
   for (const auto& mapping : variations_mappings) {
     // Set the option variable to true if the corresponding value is found in
     // the registry. Set to false otherwise (default behavior).
     DWORD value = 0;
     if (key.ReadValueDW(mapping.name, &value) == ERROR_SUCCESS) {
       DCHECK_EQ(1U, value);
       g_pre_read_options &= mapping.bit;
     }
@@ skipping 61 matching lines @@
   base::string16 group;
   key.ReadValue(L"", &group);
 
   if (!group.empty()) {
     register_synthetic_field_trial.Run(kPreReadSyntheticFieldTrialName,
                                        base::UTF16ToUTF8(group));
   }
 }
 
 }  // namespace startup_metric_utils