Hide IDBDatabase.transaction argument when not runtime enabled

Previously, the third argument was web-exposed when it should not have
been.

Bug: 1006131
Change-Id: Ie35a6e8b0e08f35e8fdf7bf297435ab6edac3cd9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1816579
Commit-Queue: enne <enne@chromium.org>
Auto-Submit: enne <enne@chromium.org>
Reviewed-by: Victor Costan <pwnall@chromium.org>
Reviewed-by: Marijn Kruisselbrink <mek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#699404}

third_party/blink/renderer/modules/indexeddb/idb_database.cc

@@ -350,6 +350,14 @@ void IDBDatabase::deleteObjectStore(const String& name,
   metadata_.object_stores.erase(object_store_id);
 }
 
+IDBTransaction* IDBDatabase::transaction(
+    ScriptState* script_state,
+    const StringOrStringSequence& store_names,
+    const String& mode,
+    ExceptionState& exception_state) {
+  return transaction(script_state, store_names, mode, nullptr, exception_state);
+}
+
 IDBTransaction* IDBDatabase::transaction(
     ScriptState* script_state,
     const StringOrStringSequence& store_names,
@@ -423,7 +431,8 @@ IDBTransaction* IDBDatabase::transaction(
 
   mojom::IDBTransactionDurability durability =
       mojom::IDBTransactionDurability::Default;
-  if (RuntimeEnabledFeatures::IDBRelaxedDurabilityEnabled() && options) {
+  if (options) {
+    DCHECK(RuntimeEnabledFeatures::IDBRelaxedDurabilityEnabled());
     if (options->durability() == "relaxed") {
       durability = mojom::IDBTransactionDurability::Relaxed;
     } else if (options->durability() == "strict") {

third_party/blink/renderer/modules/indexeddb/idb_database.h

@@ -102,6 +102,10 @@ class MODULES_EXPORT IDBDatabase final
     return createObjectStore(name, IDBKeyPath(options->keyPath()),
                              options->autoIncrement(), exception_state);
   }
+  IDBTransaction* transaction(ScriptState*,
+                              const StringOrStringSequence& store_names,
+                              const String& mode,
+                              ExceptionState&);
   IDBTransaction* transaction(ScriptState*,
                               const StringOrStringSequence& store_names,
                               const String& mode,

third_party/blink/renderer/modules/indexeddb/idb_database.idl

@@ -35,8 +35,12 @@
     readonly attribute DOMStringList objectStoreNames;
 
     [NewObject, CallWith=ScriptState, RaisesException] IDBTransaction transaction((DOMString or sequence<DOMString>) storeNames,
+                                                                                  optional IDBTransactionMode mode = "readonly");
+
+    [NewObject, CallWith=ScriptState, RaisesException, RuntimeEnabled=IDBRelaxedDurability] IDBTransaction transaction((DOMString or sequence<DOMString>) storeNames,
+
                                                                                   optional IDBTransactionMode mode = "readonly",
-                                                                                  optional IDBTransactionOptions options);
+                                                                                  IDBTransactionOptions options);
     void close();
 
     [MeasureAs=IndexedDBWrite, NewObject, RaisesException]