Remove worker pool names from TaskScheduler.TaskLatency.* histograms.

base/task_scheduler/scheduler_worker.cc

Index: base/task_scheduler/scheduler_worker.cc
diff --git a/base/task_scheduler/scheduler_worker.cc b/base/task_scheduler/scheduler_worker.cc
index 5853bf6131e46e67ea8492d1351ef0e53e7338de..970a7d4cf908a9b4aa8249f988e1ebeaed1e41ba 100644
--- a/base/task_scheduler/scheduler_worker.cc
+++ b/base/task_scheduler/scheduler_worker.cc
@@ -78,11 +78,10 @@ class SchedulerWorker::Thread : public PlatformThread::Delegate {
         continue;
       }
 
-      std::unique_ptr<Task> task = sequence->TakeTask();
-      const TaskPriority task_priority = task->traits.priority();
-      const TimeDelta task_latency = TimeTicks::Now() - task->sequenced_time;
-      if (outer_->task_tracker_->RunTask(std::move(task), sequence->token()))
-        outer_->delegate_->DidRunTaskWithPriority(task_priority, task_latency);
+      if (outer_->task_tracker_->RunTask(sequence->TakeTask(),
+                                         sequence->token())) {
+        outer_->delegate_->DidRunTask();
+      }
 
       const bool sequence_became_empty = sequence->Pop();