Reduce the number of PostTasks done by BoundedFiledNetLog.

net/log/bounded_file_net_log_observer.cc

 // Copyright 2016 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.
 
 #include "net/log/bounded_file_net_log_observer.h"
 
 #include <memory>
 #include <set>
 #include <utility>
 #include <vector>
@@ skipping 241 matching lines @@
 void BoundedFileNetLogObserver::OnAddEntry(const NetLogEntry& entry) {
   std::unique_ptr<std::string> json(new std::string);
 
   // If |entry| cannot be converted to proper JSON, ignore it.
   if (!base::JSONWriter::Write(*entry.ToValue(), json.get()))
     return;
 
   size_t queue_size = write_queue_->AddEntryToQueue(std::move(json));
 
   // If events build up in |write_queue_|, trigger the file thread to drain
-  // the queue.
-  if (queue_size >= kNumWriteQueueEvents) {
+  // the queue. Because only 1 item is added to the queue at a time, if
+  // queue_size > kNumWriteQueueEvents a task has already been posted, or will
+  // be posted.
+  if (queue_size == kNumWriteQueueEvents) {
     task_runner_->PostTask(
         FROM_HERE, base::Bind(&BoundedFileNetLogObserver::FileWriter::Flush,
                               base::Unretained(file_writer_), write_queue_));
   }
 }
 
 BoundedFileNetLogObserver::WriteQueue::WriteQueue(size_t memory_max)
     : memory_(0), memory_max_(memory_max) {}
 
 size_t BoundedFileNetLogObserver::WriteQueue::AddEntryToQueue(
@@ skipping 122 matching lines @@
   base::DeleteFile(directory_.AppendASCII("constants.json"), false);
   base::DeleteFile(directory_.AppendASCII("end_netlog.json"), false);
   for (size_t i = 0; i < total_num_files_; i++) {
     base::DeleteFile(directory_.AppendASCII("event_file_" +
                                             base::SizeTToString(i) + ".json"),
                      false);
   }
 }
 
 }  // namespace net