Revert of Adds TimeDomains to the TaskQueueManager

components/scheduler/base/task_queue.h

Index: components/scheduler/base/task_queue.h
diff --git a/components/scheduler/base/task_queue.h b/components/scheduler/base/task_queue.h
index 393cc5077374a1b4f35302de9c1e6647b8273470..abc3665e581e62d247b06dc27ffc7570ea50c959 100644
--- a/components/scheduler/base/task_queue.h
+++ b/components/scheduler/base/task_queue.h
@@ -10,7 +10,6 @@
 #include "components/scheduler/scheduler_export.h"
 
 namespace scheduler {
-class TimeDomain;
 
 class SCHEDULER_EXPORT TaskQueue : public base::SingleThreadTaskRunner {
  public:
@@ -103,7 +102,6 @@
           should_monitor_quiescence(false),
           pump_policy(TaskQueue::PumpPolicy::AUTO),
           wakeup_policy(TaskQueue::WakeupPolicy::CAN_WAKE_OTHER_QUEUES),
-          time_domain(nullptr),
           should_notify_observers(true) {}
 
     Spec SetShouldMonitorQuiescence(bool should_monitor) {
@@ -126,16 +124,10 @@
       return *this;
     }
 
-    Spec SetTimeDomain(TimeDomain* domain) {
-      time_domain = domain;
-      return *this;
-    }
-
     const char* name;
     bool should_monitor_quiescence;
     TaskQueue::PumpPolicy pump_policy;
     TaskQueue::WakeupPolicy wakeup_policy;
-    TimeDomain* time_domain;
     bool should_notify_observers;
   };
 
@@ -181,10 +173,6 @@
   virtual void RemoveTaskObserver(
       base::MessageLoop::TaskObserver* task_observer) = 0;
 
-  // Removes the task queue from the previous TimeDomain and adds it to
-  // |domain|.  This is a moderately expensive operation.
-  virtual void SetTimeDomain(const scoped_refptr<TimeDomain>& domain) = 0;
-
  protected:
   ~TaskQueue() override {}