Register a pref to control migration status

components/content_settings/core/browser/host_content_settings_map.cc

Index: components/content_settings/core/browser/host_content_settings_map.cc
diff --git a/components/content_settings/core/browser/host_content_settings_map.cc b/components/content_settings/core/browser/host_content_settings_map.cc
index 015705ebc8ea9a38646b344a50006d6e06ead63b..e5ebc789aea4f9638be14ef17ccf9112892badf8 100644
--- a/components/content_settings/core/browser/host_content_settings_map.cc
+++ b/components/content_settings/core/browser/host_content_settings_map.cc
@@ -169,7 +169,14 @@ HostContentSettingsMap::HostContentSettingsMap(PrefService* prefs,
   content_settings_providers_[DEFAULT_PROVIDER] = default_provider;
 
   MigrateKeygenSettings();
-  MigrateDomainScopedSettings();
+
+  if (prefs_->GetInteger(prefs::kContentSettingsMigrationStatus) ==
+      content_settings::NOT_MIGRATED) {
+    MigrateDomainScopedSettings();
+    prefs_->SetInteger(prefs::kContentSettingsMigrationStatus,
+                       content_settings::DONE_IN_HCSM);
+  }
+
   RecordNumberOfExceptions();
 }
 
@@ -180,6 +187,8 @@ void HostContentSettingsMap::RegisterProfilePrefs(
   content_settings::ContentSettingsRegistry::GetInstance();
 
   registry->RegisterIntegerPref(prefs::kContentSettingsWindowLastTabIndex, 0);
+  registry->RegisterIntegerPref(prefs::kContentSettingsMigrationStatus,
+                                content_settings::NOT_MIGRATED);
 
   // Register the prefs for the content settings providers.
   content_settings::DefaultProvider::RegisterProfilePrefs(registry);