Record PendingTaskCount when a backgrounded renderer is suspended.

third_party/WebKit/Source/platform/scheduler/base/task_queue_manager.h

 // Copyright 2014 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_BASE_TASK_QUEUE_MANAGER_H_
 #define THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_BASE_TASK_QUEUE_MANAGER_H_
 
 #include <map>
 
 #include "base/atomic_sequence_num.h"
@@ skipping 119 matching lines @@
 
   LazyNow CreateLazyNow() const;
 
   // Returns the currently executing TaskQueue if any. Must be called on the
   // thread this class was created on.
   TaskQueue* currently_executing_task_queue() const {
     DCHECK(main_thread_checker_.CalledOnValidThread());
     return currently_executing_task_queue_;
   }
 
+  // Return number of pending tasks in task queues.
+  size_t GetNumberOfPendingTasks() const;
+
  private:
   friend class LazyNow;
   friend class internal::TaskQueueImpl;
   friend class TaskQueueManagerTest;
 
   class DeletionSentinel : public base::RefCounted<DeletionSentinel> {
    private:
     friend class base::RefCounted<DeletionSentinel>;
     ~DeletionSentinel() {}
   };
@@ skipping 102 matching lines @@
   scoped_refptr<DeletionSentinel> deletion_sentinel_;
   base::WeakPtrFactory<TaskQueueManager> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TaskQueueManager);
 };
 
 }  // namespace scheduler
 }  // namespace blink
 
 #endif  // THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_BASE_TASK_QUEUE_MANAGER_H_