1 files changed, 19 insertions, 16 deletions

diff --git a/chromium/media/midi/task_service.cc b/chromium/media/midi/task_service.cc
index 3bb3baf01b5..563d63fbf91 100644
--- a/chromium/media/midi/task_service.cc
+++ b/chromium/media/midi/task_service.cc
@@ -12,19 +12,10 @@
 
 namespace midi {
 
-namespace {
-
-constexpr TaskService::InstanceId kInvalidInstanceId = -1;
-
-}  // namespace
-
 constexpr TaskService::RunnerId TaskService::kDefaultRunnerId;
+constexpr TaskService::InstanceId TaskService::kInvalidInstanceId;
 
-TaskService::TaskService()
-    : no_tasks_in_flight_cv_(&tasks_in_flight_lock_),
-      tasks_in_flight_(0),
-      next_instance_id_(0),
-      bound_instance_id_(kInvalidInstanceId) {
+TaskService::TaskService() : no_tasks_in_flight_cv_(&tasks_in_flight_lock_) {
   DETACH_FROM_SEQUENCE(instance_binding_sequence_checker_);
 }
 
@@ -45,10 +36,17 @@ bool TaskService::BindInstance() {
   base::AutoLock lock(lock_);
   if (bound_instance_id_ != kInvalidInstanceId)
     return false;
-  bound_instance_id_ = next_instance_id_++;
+
+  // If the InstanceId reaches to the limit, just fail rather than doing
+  // something nicer for such impractical case.
+  if (std::numeric_limits<InstanceId>::max() == next_instance_id_)
+    return false;
+
+  bound_instance_id_ = ++next_instance_id_;
 
   DCHECK(!default_task_runner_);
   default_task_runner_ = base::ThreadTaskRunnerHandle::Get();
+
   return true;
 }
 
@@ -58,16 +56,17 @@ bool TaskService::UnbindInstance() {
     base::AutoLock lock(lock_);
     if (bound_instance_id_ == kInvalidInstanceId)
       return false;
+
+    DCHECK_EQ(next_instance_id_, bound_instance_id_);
     bound_instance_id_ = kInvalidInstanceId;
 
     DCHECK(default_task_runner_);
     default_task_runner_ = nullptr;
   }
-
   // From now on RunTask will never run any task bound to the instance id.
   // But invoked tasks might be still running here. To ensure no task runs on
   // quitting this method, wait for all tasks to complete.
-  base::AutoLock tasks_in_flight_auto_lock(tasks_in_flight_lock_);
+  base::AutoLock tasks_in_flight_lock(tasks_in_flight_lock_);
   // TODO(https://crbug.com/796830): Remove sync operations on the I/O thread.
   base::ScopedAllowBaseSyncPrimitivesOutsideBlockingScope allow_wait;
   while (tasks_in_flight_ > 0)
@@ -126,6 +125,10 @@ void TaskService::PostBoundDelayedTask(RunnerId runner_id,
       delay);
 }
 
+void TaskService::OverflowInstanceIdForTesting() {
+  next_instance_id_ = std::numeric_limits<InstanceId>::max();
+}
+
 scoped_refptr<base::SingleThreadTaskRunner> TaskService::GetTaskRunner(
     RunnerId runner_id) {
   base::AutoLock lock(lock_);
@@ -154,7 +157,7 @@ void TaskService::RunTask(InstanceId instance_id,
                           RunnerId runner_id,
                           base::OnceClosure task) {
   {
-    base::AutoLock tasks_in_flight_auto_lock(tasks_in_flight_lock_);
+    base::AutoLock tasks_in_flight_lock(tasks_in_flight_lock_);
     ++tasks_in_flight_;
   }
 
@@ -162,7 +165,7 @@ void TaskService::RunTask(InstanceId instance_id,
     std::move(task).Run();
 
   {
-    base::AutoLock tasks_in_flight_auto_lock(tasks_in_flight_lock_);
+    base::AutoLock tasks_in_flight_lock(tasks_in_flight_lock_);
     --tasks_in_flight_;
     DCHECK_GE(tasks_in_flight_, 0);
     if (tasks_in_flight_ == 0)