Make sure scheduler shutdown prevents idle tasks from running

third_party/WebKit/Source/platform/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 THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_CHILD_IDLE_HELPER_H_
 #define THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_CHILD_IDLE_HELPER_H_
 
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "platform/scheduler/base/cancelable_closure_holder.h"
@@ skipping 76 matching lines @@
   // outlive it.
   IdleHelper(
       SchedulerHelper* helper,
       Delegate* delegate,
       const char* tracing_category,
       const char* disabled_by_default_tracing_category,
       const char* idle_period_tracing_name,
       base::TimeDelta required_quiescence_duration_before_long_idle_period);
   ~IdleHelper() override;
 
+  // Prevents any further idle tasks from running.
+  void Shutdown();
+
   // Returns the idle task runner. Tasks posted to this runner may be reordered
   // relative to other task types and may be starved for an arbitrarily long
   // time if no idle time is available.
   scoped_refptr<SingleThreadIdleTaskRunner> IdleTaskRunner();
 
   // If |required_quiescence_duration_before_long_idle_period_| is zero then
   // immediately initiate a long idle period, otherwise check if any tasks have
   // run recently and if so, check again after a delay of
   // |required_quiescence_duration_before_long_idle_period_|.
   // Calling this function will end any previous idle period immediately, and
@@ skipping 115 matching lines @@
 
   CancelableClosureHolder enable_next_long_idle_period_closure_;
   CancelableClosureHolder on_idle_task_posted_closure_;
 
   State state_;
 
   base::TimeDelta required_quiescence_duration_before_long_idle_period_;
 
   const char* disabled_by_default_tracing_category_;
 
+  bool is_shutdown_;
+
   base::WeakPtr<IdleHelper> weak_idle_helper_ptr_;
   base::WeakPtrFactory<IdleHelper> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(IdleHelper);
 };
 
 }  // namespace scheduler
 }  // namespace blink
 
 #endif  // THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_CHILD_IDLE_HELPER_H_