Add an api to disable recording task delay histogrames

third_party/WebKit/Source/platform/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 THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_CHILD_SCHEDULER_HELPER_H_
 #define THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_CHILD_SCHEDULER_HELPER_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
@@ skipping 12 matching lines @@
  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;
 
+  // There is a small overhead to recording task delay histograms, we may not
+  // wish to do this on all threads.
+  void SetRecordTaskDelayHistograms(bool record_task_delay_histograms);
+
   // TaskQueueManager::Observer implementation:
   void OnUnregisterTaskQueue(const scoped_refptr<TaskQueue>& queue) override;
   void OnTriedToExecuteBlockedTask(const TaskQueue& queue,
                                    const base::PendingTask& task) override;
 
   // Returns the default task runner.
   scoped_refptr<TaskQueue> DefaultTaskRunner();
 
   // Returns the control task runner.  Tasks posted to this runner are executed
   // with the highest priority. Care must be taken to avoid starvation of other
@@ skipping 73 matching lines @@
   const char* tracing_category_;
   const char* disabled_by_default_tracing_category_;
 
   DISALLOW_COPY_AND_ASSIGN(SchedulerHelper);
 };
 
 }  // namespace scheduler
 }  // namespace blink
 
 #endif  // THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_CHILD_SCHEDULER_HELPER_H_