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

components/startup_metric_utils/common/pre_read_field_trial_utils_win.cc

Index: components/startup_metric_utils/common/pre_read_field_trial_utils_win.cc
diff --git a/components/startup_metric_utils/common/pre_read_field_trial_utils_win.cc b/components/startup_metric_utils/common/pre_read_field_trial_utils_win.cc
index 6aa82a19d93e59d8da9f80ca767206fe5f438be6..d24ae210c29168f4656af3841cc153bd7c2478a5 100644
--- a/components/startup_metric_utils/common/pre_read_field_trial_utils_win.cc
+++ b/components/startup_metric_utils/common/pre_read_field_trial_utils_win.cc
@@ -31,6 +31,7 @@ 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";
@@ -43,16 +44,8 @@ base::string16 GetPreReadRegistryPath(
 
 }  // namespace
 
-void GetPreReadOptions(const base::string16& product_registry_path,
-                       bool* no_pre_read,
-                       bool* high_priority,
-                       bool* only_if_cold,
-                       bool* prefetch_virtual_memory) {
+int GetPreReadOptions(const base::string16& product_registry_path) {
   DCHECK(!product_registry_path.empty());
-  DCHECK(no_pre_read);
-  DCHECK(high_priority);
-  DCHECK(only_if_cold);
-  DCHECK(prefetch_virtual_memory);
 
   // Open the PreRead field trial's registry key.
   const base::string16 registry_path =
@@ -63,21 +56,28 @@ void GetPreReadOptions(const base::string16& product_registry_path,
   // Set the PreRead field trial's options.
   struct VariationMapping {
     const base::char16* name;
-    bool* variable;
+    PreReadOptions bit;
   } const variations_mappings[] = {
-      {kNoPreReadVariationName, no_pre_read},
-      {kHighPriorityVariationName, high_priority},
-      {kOnlyIfColdVariationName, only_if_cold},
-      {kPrefetchVirtualMemoryVariationName, prefetch_virtual_memory},
+      {kNoPreReadVariationName, NO_PRE_READ},
+      {kHighPriorityVariationName, HIGH_PRIORITY},
+      {kOnlyIfColdVariationName, ONLY_IF_COLD},
+      {kPrefetchVirtualMemoryVariationName, PREFETCH_VIRTUAL_MEMORY},
+      {kNoPrefetchArgumentVariationName, NO_PREFETCH_ARGUMENT},
   };
 
+  int options = 0;
+
   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;
-    *mapping.variable = key.ReadValueDW(mapping.name, &value) == ERROR_SUCCESS;
-    DCHECK(!*mapping.variable || value == 1);
+    if (key.ReadValueDW(mapping.name, &value) == ERROR_SUCCESS) {
+      DCHECK(value == 1);
+      options &= mapping.bit;
+    }
   }
+
+  return options;
 }
 
 void UpdatePreReadOptions(const base::string16& product_registry_path) {