Add MessageLoop::AssertIdle(). Use in ChromeOS audio threads.

base/message_loop.cc

Index: base/message_loop.cc
diff --git a/base/message_loop.cc b/base/message_loop.cc
index 518a0fd25989864f1dcbe539f10c4f51e5b44384..220d2ea5a770acf7bbd52a6f25036d604a32475c 100644
--- a/base/message_loop.cc
+++ b/base/message_loop.cc
@@ -286,6 +286,11 @@ void MessageLoop::RemoveTaskObserver(TaskObserver* task_observer) {
   task_observers_.RemoveObserver(task_observer);
 }
 
+void MessageLoop::AssertIdle() const {
+  base::AutoLock lock(incoming_queue_lock_);
+  DCHECK(incoming_queue_.empty());

[darin (slow to review), 2011/01/25 17:07:43]

what about the work_queue_?

[willchan no longer on Chromium, 2011/01/25 17:12:01]

See my comment in the .h file:
// Asserts that the MessageLoop is "idle". in reality, we only check
// |incoming_queue_|, since we don't want to lock |work_queue_|.

|work_queue_| is only ever touched on the thread the MessageLoop runs on, so
unless I want to add a bunch of locks, I think it's unsafe to access. I am
concerned that an unlocked .empty() operation on |work_queue_| may lead to
crashes, although I guess that's implementation specific.

+}
+
 //------------------------------------------------------------------------------
 
 // Runs the loop in two different SEH modes: