Report expected task queueing time via UMA

components/scheduler/child/scheduler_helper.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_SCHEDULER_CHILD_SCHEDULER_HELPER_H_
 #define COMPONENTS_SCHEDULER_CHILD_SCHEDULER_HELPER_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
 #include "base/time/tick_clock.h"
 #include "components/scheduler/base/task_queue_manager.h"
 #include "components/scheduler/base/task_queue_selector.h"
 #include "components/scheduler/scheduler_export.h"
 
 namespace base {
 class TickClock;
 }
 
 namespace scheduler {
 
 class SchedulerTqmDelegate;
 
 // Common scheduler functionality for default tasks.
-class SCHEDULER_EXPORT SchedulerHelper : public TaskQueueManager::Observer {
+class SCHEDULER_EXPORT SchedulerHelper
+    : public TaskQueueManager::Observer {
  public:
   // Category strings must have application lifetime (statics or
   // literals). They may not include " chars.
   SchedulerHelper(
       scoped_refptr<SchedulerTqmDelegate> task_queue_manager_delegate,
       const char* tracing_category,
       const char* disabled_by_default_tracing_category,
       const char* disabled_by_default_verbose_tracing_category);
   ~SchedulerHelper() override;
 
@@ skipping 14 matching lines @@
   // are executed with the highest priority but do not cause the scheduler to
   // wake up. Care must be taken to avoid starvation of other task queues.
   scoped_refptr<TaskQueue> ControlAfterWakeUpTaskRunner();
 
   // Adds or removes a task observer from the scheduler. The observer will be
   // notified before and after every executed task. These functions can only be
   // called on the thread this class was created on.
   void AddTaskObserver(base::MessageLoop::TaskObserver* task_observer);
   void RemoveTaskObserver(base::MessageLoop::TaskObserver* task_observer);
 
+  void SetTaskTimeTracker(TaskTimeTracker* task_time_tracker) {
+    if (task_queue_manager_)
+      task_queue_manager_->SetTaskTimeTracker(task_time_tracker);
+  }
+
   // Shuts down the scheduler by dropping any remaining pending work in the work
   // queues. After this call any work posted to the task runners will be
   // silently dropped.
   void Shutdown();
 
   // Returns true if Shutdown() has been called. Otherwise returns false.
   bool IsShutdown() const { return !task_queue_manager_.get(); }
 
   void CheckOnValidThread() const {
     DCHECK(thread_checker_.CalledOnValidThread());
@@ skipping 46 matching lines @@
   Observer* observer_;  // NOT OWNED
   const char* tracing_category_;
   const char* disabled_by_default_tracing_category_;
 
   DISALLOW_COPY_AND_ASSIGN(SchedulerHelper);
 };
 
 }  // namespace scheduler
 
 #endif  // COMPONENTS_SCHEDULER_CHILD_SCHEDULER_HELPER_H_