[IndexedDB] Adding transaction and value support to observers

content/browser/indexed_db/indexed_db_transaction_coordinator.cc

Index: content/browser/indexed_db/indexed_db_transaction_coordinator.cc
diff --git a/content/browser/indexed_db/indexed_db_transaction_coordinator.cc b/content/browser/indexed_db/indexed_db_transaction_coordinator.cc
index 68e01728813500240ba1625873519d9073cc87ea..80345303ab195efadd7a765b33fb8d8b154033b1 100644
--- a/content/browser/indexed_db/indexed_db_transaction_coordinator.cc
+++ b/content/browser/indexed_db/indexed_db_transaction_coordinator.cc
@@ -27,6 +27,17 @@ void IndexedDBTransactionCoordinator::DidCreateTransaction(
   ProcessQueuedTransactions();
 }
 
+// Observer transactions jump to the front of the queue.
+void IndexedDBTransactionCoordinator::DidCreateObserverTransaction(
+    IndexedDBTransaction* transaction) {
+  DCHECK(!queued_transactions_.count(transaction));
+  DCHECK(!started_transactions_.count(transaction));
+  DCHECK_EQ(IndexedDBTransaction::CREATED, transaction->state());
+
+  started_transactions_.insert_front(transaction);
+  ProcessQueuedTransactions();
+}
+
 void IndexedDBTransactionCoordinator::DidFinishTransaction(
     IndexedDBTransaction* transaction) {
   if (queued_transactions_.count(transaction)) {