tracing: the client lib of the tracing service

services/resource_coordinator/public/cpp/tracing/chrome_agent.h

+// Copyright 2017 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 SERVICES_RESOURCE_COORDINATOR_PUBLIC_CPP_TRACING_CHROME_AGENT_H_
+#define SERVICES_RESOURCE_COORDINATOR_PUBLIC_CPP_TRACING_CHROME_AGENT_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/ref_counted_memory.h"

[Primiano Tucci (use gerrit), 2017/05/16 04:45:11]

not sure you need this

[chiniforooshan, 2017/05/16 15:14:45]

For base::RefCountedString.

+#include "base/threading/thread_checker.h"
+#include "base/values.h"

[Primiano Tucci (use gerrit), 2017/05/16 04:45:11]

I think you can just forward declare base::DictionaryValue and move the include
to the .cc file (if for any reason doesn't work because of the callback ignore
this comment)

[chiniforooshan, 2017/05/16 15:14:45]

Done.

+#include "mojo/public/cpp/bindings/binding.h"
+#include "services/resource_coordinator/public/cpp/resource_coordinator_export.h"
+#include "services/resource_coordinator/public/interfaces/tracing/tracing.mojom.h"
+#include "services/service_manager/public/cpp/connector.h"
+
+namespace tracing {
+
+class SERVICES_RESOURCE_COORDINATOR_PUBLIC_CPP_EXPORT ChromeAgent

[Primiano Tucci (use gerrit), 2017/05/16 04:45:11]

Ahhhhh now I understand. this is not a generic agent interface. This is the
actual chrome traece event agent.
sorry i didn't understand this in the doc.
I agree with you that ChromeTraceEventAgent, or ChromeTracingAgent is also a
stronger and more indicative name.
As you prefer though, I feel I already asked you to rename this once. sorry my
misunderstanding in the doc,I thought we were talking about "how should the
generic interface be called?"

[chiniforooshan, 2017/05/16 15:14:45]

Done.

+    : public mojom::Agent {
+ public:
+  using MetadataGeneratorFunction =
+      base::RepeatingCallback<std::unique_ptr<base::DictionaryValue>()>;
+
+  static ChromeAgent* GetOrCreateInstance(
+      mojom::AgentRegistryPtr agent_registry);
+
+  void AddMetadataGeneratorFunction(MetadataGeneratorFunction generator);
+
+ private:
+  friend std::default_delete<ChromeAgent>;  // For Testing
+  friend class ChromeAgentTest;             // For Testing
+
+  explicit ChromeAgent(mojom::AgentRegistryPtr agent_registry);
+  ~ChromeAgent() override;
+
+  // mojom::Agent
+  void StartTracing(const std::string& config,
+                    mojom::RecorderPtr recorder,
+                    const StartTracingCallback& callback) override;
+  void StopAndFlush() override;
+  void RequestClockSyncMarker(
+      const std::string& sync_id,
+      const RequestClockSyncMarkerCallback& callback) override;
+  void RequestBufferStatus(
+      const RequestBufferStatusCallback& callback) override;
+  void GetCategories(const GetCategoriesCallback& callback) override;
+
+  void SendChunk(const scoped_refptr<base::RefCountedString>& events_str,
+                 bool has_more_events);
+
+  mojo::Binding<mojom::Agent> binding_;
+  mojom::RecorderPtr recorder_;
+  std::vector<MetadataGeneratorFunction> metadata_generator_functions_;
+
+  base::ThreadChecker thread_checker_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChromeAgent);
+};
+
+}  // namespace tracing
+#endif  // SERVICES_RESOURCE_COORDINATOR_PUBLIC_CPP_TRACING_CHROME_AGENT_H_