Rewrite base::Bind into base::BindOnce on trivial cases in base

base/trace_event/trace_event_system_stats_monitor.cc

 // Copyright 2013 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 "base/trace_event/trace_event_system_stats_monitor.h"
 
 #include <memory>
 
 #include "base/debug/leak_annotations.h"
 #include "base/json/json_writer.h"
@@ skipping 61 matching lines @@
 
 void TraceEventSystemStatsMonitor::OnTraceLogEnabled() {
   // Check to see if system tracing is enabled.
   bool enabled;
 
   TRACE_EVENT_CATEGORY_GROUP_ENABLED(TRACE_DISABLED_BY_DEFAULT(
                                      "system_stats"), &enabled);
   if (!enabled)
     return;
   task_runner_->PostTask(
-      FROM_HERE,
-      base::Bind(&TraceEventSystemStatsMonitor::StartProfiling,
-                 weak_factory_.GetWeakPtr()));
+      FROM_HERE, base::BindOnce(&TraceEventSystemStatsMonitor::StartProfiling,
+                                weak_factory_.GetWeakPtr()));
 }
 
 void TraceEventSystemStatsMonitor::OnTraceLogDisabled() {
   task_runner_->PostTask(
-      FROM_HERE,
-      base::Bind(&TraceEventSystemStatsMonitor::StopProfiling,
-                 weak_factory_.GetWeakPtr()));
+      FROM_HERE, base::BindOnce(&TraceEventSystemStatsMonitor::StopProfiling,
+                                weak_factory_.GetWeakPtr()));
 }
 
 void TraceEventSystemStatsMonitor::StartProfiling() {
   // Watch for the tracing framework sending enabling more than once.
   if (dump_timer_.IsRunning())
     return;
 
   dump_timer_.Start(FROM_HERE,
                     TimeDelta::FromMilliseconds(TraceEventSystemStatsMonitor::
                                                 kSamplingIntervalMilliseconds),
@@ skipping 23 matching lines @@
 
 void AppendSystemProfileAsTraceFormat(const SystemMetrics& system_metrics,
                                       std::string* output) {
   std::string tmp;
   base::JSONWriter::Write(*system_metrics.ToValue(), &tmp);
   *output += tmp;
 }
 
 }  // namespace trace_event
 }  // namespace base