arc: enable Android tracing in verified-boot mode

chromeos/dbus/arc_trace_agent.h

Index: chromeos/dbus/arc_trace_agent.h
diff --git a/chromeos/dbus/arc_trace_agent.h b/chromeos/dbus/arc_trace_agent.h
new file mode 100644
index 0000000000000000000000000000000000000000..e54536a33cc60585e4504acf02de550ca86757fd
--- /dev/null
+++ b/chromeos/dbus/arc_trace_agent.h
@@ -0,0 +1,74 @@
+// 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.
+
+#ifndef CHROMEOS_DBUS_ARC_TRACE_AGENT_H_
+#define CHROMEOS_DBUS_ARC_TRACE_AGENT_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/task_runner.h"
+#include "base/trace_event/trace_event.h"
+#include "base/trace_event/tracing_agent.h"
+#include "chromeos/dbus/dbus_client.h"
+#include "chromeos/dbus/pipe_reader.h"
+#include "dbus/object_proxy.h"
+
+namespace chromeos {
+
+// A wrapper for controlling system tracing on Chrome OS.
+class ArcTraceAgent
+    : public base::trace_event::TracingAgent,
+      public DBusClient {
+ public:
+  class ArcTraceBridge {

[Luis Héctor Chávez, 2016/12/27 19:16:00]

This is a delegate, so maybe call it Delegate.

[shunhsingou, 2016/12/28 09:15:16]

Done.

+   public:
+    virtual void StartTracing(
+        const base::trace_event::TraceConfig& trace_config) = 0;
+
+    virtual void StopTracing() = 0;
+  };
+
+  ~ArcTraceAgent();
+
+  void SetArcTraceBridge(ArcTraceBridge* bridge);
+
+  // Overrides TracingAgent functions.

[Luis Héctor Chávez, 2016/12/27 19:16:00]

// base::trace_event::TracingAgent overrides:

(and remove the empty lines between the overridden methods).

[shunhsingou, 2016/12/28 09:15:16]

Done.

+  std::string GetTracingAgentName() override;
+
+  std::string GetTraceEventLabel() override;
+
+  void StopAgentTracing(const StopAgentTracingCallback& callback) override;
+
+  void StartAgentTracing(const base::trace_event::TraceConfig& trace_config,
+                         const StartAgentTracingCallback& callback) override;
+
+  void SetStopAgentTracingTaskRunner(
+      scoped_refptr<base::TaskRunner> task_runner);
+
+  void Init(dbus::Bus* bus) override;

[Luis Héctor Chávez, 2016/12/27 19:16:00]

// DBusClient overrides:

[shunhsingou, 2016/12/28 09:15:16]

Done.

+
+  static ArcTraceAgent* Create();
+
+ private:
+  ArcTraceAgent();
+
+  DISALLOW_COPY_AND_ASSIGN(ArcTraceAgent);

[Luis Héctor Chávez, 2016/12/27 19:16:00]

This should be at the very end of a class.

[shunhsingou, 2016/12/28 09:15:16]

Done.

+
+  void OnStartMethod(dbus::Response* response);
+  void OnIOComplete();
+  void OnStopAgentTracing(dbus::Response* response);
+
+  ArcTraceBridge* arc_trace_bridge_;

[Luis Héctor Chávez, 2016/12/27 19:16:00]

Please note who owns all the raw pointers.

[shunhsingou, 2016/12/28 09:15:16]

Done.

+  dbus::ObjectProxy* debugdaemon_proxy_;
+  std::unique_ptr<PipeReaderForString> pipe_reader_;
+  base::WeakPtrFactory<ArcTraceAgent> weak_ptr_factory_;

[Luis Héctor Chávez, 2016/12/27 19:16:00]

WeakPtrFactories should always be the very last entries of a class (as noted in
their documentation:
https://cs.chromium.org/chromium/src/base/memory/weak_ptr.h?q=base::WeakPtrFa...
)

[shunhsingou, 2016/12/28 09:15:16]

Done.

+  scoped_refptr<base::TaskRunner> stop_agent_tracing_task_runner_;
+  StopAgentTracingCallback callback_;

[Luis Héctor Chávez, 2016/12/27 19:16:00]

nit: stop_callback_

[shunhsingou, 2016/12/28 09:15:16]

Done.

+};
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_DBUS_ARC_TRACE_AGENT_H_