Add ScopedTaskEnvironment::ExecutionControlMode.

base/task_scheduler/task_tracker.cc

Index: base/task_scheduler/task_tracker.cc
diff --git a/base/task_scheduler/task_tracker.cc b/base/task_scheduler/task_tracker.cc
index 55230aa93742ee3c58da9d43a2a67dc72d452cd8..5509e3219cb563bc9063c76d4dea6b2b5af64d31 100644
--- a/base/task_scheduler/task_tracker.cc
+++ b/base/task_scheduler/task_tracker.cc
@@ -388,6 +388,10 @@ bool TaskTracker::IsPostingBlockShutdownTaskAfterShutdownAllowed() {
 }
 #endif
 
+int TaskTracker::GetNumPendingUndelayedTasksForTesting() const {
+  return subtle::Acquire_Load(&num_pending_undelayed_tasks_);

[gab, 2017/05/23 15:26:13]

Reason to Acquire_Load?

[fdoray, 2017/05/25 19:17:33]

I would have liked to Acquire_NoBarrier, but this function doesn't exist. Cannot
return |num_pending_undelayed_tasks_| directly because of
https://cs.chromium.org/chromium/src/base/atomicops.h?l=19

[gab, 2017/05/25 19:29:29]

As mentioned offline there is NoBarrier_Load

[fdoray, 2017/05/25 20:06:44]

Done.

+}
+
 bool TaskTracker::BeforePostTask(TaskShutdownBehavior shutdown_behavior) {
   if (shutdown_behavior == TaskShutdownBehavior::BLOCK_SHUTDOWN) {
     // BLOCK_SHUTDOWN tasks block shutdown between the moment they are posted