tracing: Make ConvertableToTraceFormat move-only scoped_ptr

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 "base/debug/leak_annotations.h"
 #include "base/json/json_writer.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/threading/thread_local_storage.h"
 #include "base/trace_event/trace_event.h"
 
 namespace base {
 namespace trace_event {
 
 namespace {
 
 /////////////////////////////////////////////////////////////////////////////
 // Holds profiled system stats until the tracing system needs to serialize it.
 class SystemStatsHolder : public base::trace_event::ConvertableToTraceFormat {
  public:
   SystemStatsHolder() { }
+  ~SystemStatsHolder() override {}
 
   // Fills system_metrics_ with profiled system memory and disk stats.
   // Uses the previous stats to compute rates if this is not the first profile.
   void GetSystemProfilingStats();
 
   // base::trace_event::ConvertableToTraceFormat overrides:
   void AppendAsTraceFormat(std::string* out) const override {
     AppendSystemProfileAsTraceFormat(system_stats_, out);
   }
 
  private:
-  ~SystemStatsHolder() override {}
-
   SystemMetrics system_stats_;
 
   DISALLOW_COPY_AND_ASSIGN(SystemStatsHolder);
 };
 
 void SystemStatsHolder::GetSystemProfilingStats() {
   system_stats_ = SystemMetrics::Sample();
 }
 
 }  // namespace
@@ skipping 46 matching lines @@
   dump_timer_.Start(FROM_HERE,
                     TimeDelta::FromMilliseconds(TraceEventSystemStatsMonitor::
                                                 kSamplingIntervalMilliseconds),
                     base::Bind(&TraceEventSystemStatsMonitor::
                                DumpSystemStats,
                                weak_factory_.GetWeakPtr()));
 }
 
 // If system tracing is enabled, dumps a profile to the tracing system.
 void TraceEventSystemStatsMonitor::DumpSystemStats() {
-  scoped_refptr<SystemStatsHolder> dump_holder = new SystemStatsHolder();
+  scoped_ptr<SystemStatsHolder> dump_holder(new SystemStatsHolder());
   dump_holder->GetSystemProfilingStats();
 
   TRACE_EVENT_OBJECT_SNAPSHOT_WITH_ID(
       TRACE_DISABLED_BY_DEFAULT("system_stats"),
-      "base::TraceEventSystemStatsMonitor::SystemStats",
-      this,
-      scoped_refptr<ConvertableToTraceFormat>(dump_holder));
+      "base::TraceEventSystemStatsMonitor::SystemStats", this,
+      std::move(dump_holder));
 }
 
 void TraceEventSystemStatsMonitor::StopProfiling() {
   dump_timer_.Stop();
 }
 
 bool TraceEventSystemStatsMonitor::IsTimerRunningForTest() const {
   return dump_timer_.IsRunning();
 }
 
 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