IndexedDB: Prevent store/index deletion from racing ahead of use

content/browser/indexed_db/indexed_db_transaction.cc

Index: content/browser/indexed_db/indexed_db_transaction.cc
diff --git a/content/browser/indexed_db/indexed_db_transaction.cc b/content/browser/indexed_db/indexed_db_transaction.cc
index bb7fc03c5bf07f4461db299134a56c5a417d4694..457a7807726c54bac4326ca933793ec79c38d5d4 100644
--- a/content/browser/indexed_db/indexed_db_transaction.cc
+++ b/content/browser/indexed_db/indexed_db_transaction.cc
@@ -86,18 +86,6 @@ IndexedDBTransaction::~IndexedDBTransaction() {
   DCHECK(abort_task_stack_.empty());
 }
 
-void IndexedDBTransaction::ScheduleTask(Operation task, Operation abort_task) {
-  if (state_ == FINISHED)
-    return;
-
-  timeout_timer_.Stop();
-  used_ = true;
-  task_queue_.push(task);
-  ++diagnostics_.tasks_scheduled;
-  abort_task_stack_.push(abort_task);
-  RunTasksIfStarted();
-}
-
 void IndexedDBTransaction::ScheduleTask(IndexedDBDatabase::TaskType type,
                                         Operation task) {
   if (state_ == FINISHED)
@@ -114,6 +102,12 @@ void IndexedDBTransaction::ScheduleTask(IndexedDBDatabase::TaskType type,
   RunTasksIfStarted();

[cmumford, 2014/05/13 21:56:24]

Will PostTask (run by RunTasksIfStarted) ever run the task right away - or will
it always post it to the queue? If so then might we have a case where code calls
ScheduleTask followed by ScheduleAbortTask and the abort isn't run?

[ericu, 2014/05/14 01:08:00]

No, PostTask always queues a task for asynchronous execution; it never runs the
task directly.

 }
 
+void IndexedDBTransaction::ScheduleAbortTask(Operation abort_task) {
+  DCHECK_NE(FINISHED, state_);
+  DCHECK(used_);
+  abort_task_stack_.push(abort_task);
+}
+
 void IndexedDBTransaction::RunTasksIfStarted() {
   DCHECK(used_);