Revert of Pass SequencedTaskRunner to PowerSaveBlocker for ui/file operations

content/browser/power_save_blocker_impl.h

Index: content/browser/power_save_blocker_impl.h
diff --git a/content/browser/power_save_blocker_impl.h b/content/browser/power_save_blocker_impl.h
index 5baf95096d2161dced25ed68c77e4aea91d08ef7..a01fc60928a7230c0eb87215291430287bdb56ff 100644
--- a/content/browser/power_save_blocker_impl.h
+++ b/content/browser/power_save_blocker_impl.h
@@ -18,12 +18,9 @@
 
 class PowerSaveBlockerImpl : public PowerSaveBlocker {
  public:
-  PowerSaveBlockerImpl(
-      PowerSaveBlockerType type,
-      Reason reason,
-      const std::string& description,
-      scoped_refptr<base::SequencedTaskRunner> ui_task_runner,
-      scoped_refptr<base::SequencedTaskRunner> blocking_task_runner);
+  PowerSaveBlockerImpl(PowerSaveBlockerType type,
+                       Reason reason,
+                       const std::string& description);
   ~PowerSaveBlockerImpl() override;
 
 #if defined(OS_ANDROID)
@@ -55,9 +52,6 @@
   scoped_refptr<Delegate> freedesktop_suspend_delegate_;
 #endif
 
-  scoped_refptr<base::SequencedTaskRunner> ui_task_runner_;
-  scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
-
   DISALLOW_COPY_AND_ASSIGN(PowerSaveBlockerImpl);
 };