Revert of Tests: Simplify SequencedWorkerPoolOwner, call Shutdown on destructor.

base/test/sequenced_worker_pool_owner.h

Index: base/test/sequenced_worker_pool_owner.h
diff --git a/base/test/sequenced_worker_pool_owner.h b/base/test/sequenced_worker_pool_owner.h
index 20bffb1bc8dde9b217dec6719619dc40e833a604..bf5f2f766e151e29ff7b2a78780e01c5c5715fc4 100644
--- a/base/test/sequenced_worker_pool_owner.h
+++ b/base/test/sequenced_worker_pool_owner.h
@@ -12,7 +12,6 @@
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
-#include "base/run_loop.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/sequenced_worker_pool.h"
 
@@ -26,9 +25,6 @@
 // strange races with other tests that touch global stuff (like histograms and
 // logging).  However, this requires that nothing else on this thread holds a
 // ref to the pool when the SequencedWorkerPoolOwner is destroyed.
-//
-// This class calls Shutdown on the owned SequencedWorkerPool in the destructor.
-// Tests may themselves call Shutdown earlier to test shutdown behavior.
 class SequencedWorkerPoolOwner : public SequencedWorkerPool::TestingObserver {
  public:
   SequencedWorkerPoolOwner(size_t max_threads,
@@ -50,11 +46,7 @@
   void WillWaitForShutdown() override;
   void OnDestruct() override;
 
-  // Used to run the current thread's message loop until the
-  // SequencedWorkerPool's destruction has been verified.
-  base::RunLoop exit_loop_;
   MessageLoop* const constructor_message_loop_;
-
   scoped_refptr<SequencedWorkerPool> pool_;
   Closure will_wait_for_shutdown_callback_;