V4Only: In V4Only mode use PVer4 for all SafeBrowsing operations

components/safe_browsing_db/v4_feature_list.cc

Index: components/safe_browsing_db/v4_feature_list.cc
diff --git a/components/safe_browsing_db/v4_feature_list.cc b/components/safe_browsing_db/v4_feature_list.cc
index 9f33f9fae92fe8af64cc70169b200eb76033b1ab..323ad4db74f396de0e85e3b07dd198e6735764ec 100644
--- a/components/safe_browsing_db/v4_feature_list.cc
+++ b/components/safe_browsing_db/v4_feature_list.cc
@@ -17,17 +17,26 @@ const base::Feature kLocalDatabaseManagerEnabled{
 const base::Feature kV4HybridEnabled{"SafeBrowsingV4HybridEnabled",
                                      base::FEATURE_DISABLED_BY_DEFAULT};
 
+const base::Feature kV4OnlyEnabled{"SafeBrowsingV4OnlyEnabled",
+                                   base::FEATURE_DISABLED_BY_DEFAULT};
+
 }  // namespace
 
 bool IsLocalDatabaseManagerEnabled() {
   return base::FeatureList::IsEnabled(kLocalDatabaseManagerEnabled) ||
-         IsV4HybridEnabled();
+         IsV4HybridEnabled() || IsV4OnlyEnabled();
 }
 
 bool IsV4HybridEnabled() {
   return base::FeatureList::IsEnabled(kV4HybridEnabled);
 }
 
+bool IsV4OnlyEnabled() {
+  // TODO(vakh): Enable this only when all the lists can be synced from the
+  // server. See http://b/33182208
+  return base::FeatureList::IsEnabled(kV4OnlyEnabled);
+}
+
 }  // namespace V4FeatureList
 
 }  // namespace safe_browsing