[scheduler]: Fix tracing issues with nested IdlePeriod trace events.

components/scheduler/child/idle_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_IDLE_HELPER_H_
 #define COMPONENTS_SCHEDULER_CHILD_IDLE_HELPER_H_
 
 #include "base/message_loop/message_loop.h"
 #include "components/scheduler/child/cancelable_closure_holder.h"
 #include "components/scheduler/child/scheduler_helper.h"
@@ skipping 128 matching lines @@
     void UpdateState(IdlePeriodState new_state,
                      base::TimeTicks new_deadline,
                      base::TimeTicks optional_now);
     bool IsIdlePeriodPaused() const;
 
     IdlePeriodState idle_period_state() const;
     base::TimeTicks idle_period_deadline() const;
 
     void TraceIdleIdleTaskStart();
     void TraceIdleIdleTaskEnd();
-    void TraceEventIdlePeriodStateChange(IdlePeriodState new_state,
-                                         base::TimeTicks new_deadline,
-                                         base::TimeTicks optional_now);
 
    private:
+    void TraceEventIdlePeriodStateChange(IdlePeriodState new_state,
+                                         bool new_running_idle_task,
+                                         base::TraceTicks new_deadline,
+                                         base::TraceTicks optional_now);
+
     SchedulerHelper* helper_;  // NOT OWNED
     Delegate* delegate_;       // NOT OWNED
 
     IdlePeriodState idle_period_state_;
     base::TimeTicks idle_period_deadline_;
 
     base::TraceTicks idle_period_deadline_for_tracing_;
     base::TraceTicks last_idle_task_trace_time_;
-    bool nestable_events_started_;
+    bool idle_period_trace_event_started_;
+    bool running_idle_task_for_tracing_;
     const char* tracing_category_;
     const char* disabled_by_default_tracing_category_;
     const char* idle_period_tracing_name_;
 
     DISALLOW_COPY_AND_ASSIGN(State);
   };
 
   // The minimum duration of an idle period.
   static const int kMinimumIdlePeriodDurationMillis = 1;
 
@@ skipping 36 matching lines @@
 
   base::WeakPtr<IdleHelper> weak_idle_helper_ptr_;
   base::WeakPtrFactory<IdleHelper> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(IdleHelper);
 };
 
 }  // namespace scheduler
 
 #endif  // COMPONENTS_SCHEDULER_CHILD_IDLE_HELPER_H_