Revert of Redirect the MessageLoop's task runner to the renderer scheduler

components/scheduler/test/lazy_scheduler_message_loop_delegate_for_tests.h

Index: components/scheduler/test/lazy_scheduler_message_loop_delegate_for_tests.h
diff --git a/components/scheduler/test/lazy_scheduler_message_loop_delegate_for_tests.h b/components/scheduler/test/lazy_scheduler_message_loop_delegate_for_tests.h
index 5f2eaec2e78db34f816378193c7d75498a25eb62..a727a6dd8be1b53ccafd397aa475629b448b346b 100644
--- a/components/scheduler/test/lazy_scheduler_message_loop_delegate_for_tests.h
+++ b/components/scheduler/test/lazy_scheduler_message_loop_delegate_for_tests.h
@@ -6,7 +6,7 @@
 #define COMPONENTS_SCHEDULER_TEST_LAZY_SCHEDULER_MESSAGE_LOOP_DELEGATE_FOR_TESTS_H_
 
 #include "base/message_loop/message_loop.h"
-#include "components/scheduler/child/scheduler_task_runner_delegate.h"
+#include "components/scheduler/child/nestable_single_thread_task_runner.h"
 
 namespace scheduler {
 
@@ -18,14 +18,11 @@
 // TODO(skyostil): Fix the relevant test suites and remove this class
 // (crbug.com/495659).
 class LazySchedulerMessageLoopDelegateForTests
-    : public SchedulerTaskRunnerDelegate {
+    : public NestableSingleThreadTaskRunner {
  public:
   static scoped_refptr<LazySchedulerMessageLoopDelegateForTests> Create();
 
-  // SchedulerTaskRunnerDelegate implementation
-  void SetDefaultTaskRunner(
-      scoped_refptr<base::SingleThreadTaskRunner> task_runner) override;
-  void RestoreDefaultTaskRunner() override;
+  // NestableSingleThreadTaskRunner implementation
   bool PostDelayedTask(const tracked_objects::Location& from_here,
                        const base::Closure& task,
                        base::TimeDelta delay) override;
@@ -52,10 +49,6 @@
   // owned.
   mutable base::hash_set<base::MessageLoop::TaskObserver*> pending_observers_;
 
-  // A task runner which hasn't yet been overridden in the message loop.
-  mutable scoped_refptr<base::SingleThreadTaskRunner> pending_task_runner_;
-  mutable scoped_refptr<base::SingleThreadTaskRunner> original_task_runner_;
-
   DISALLOW_COPY_AND_ASSIGN(LazySchedulerMessageLoopDelegateForTests);
 };