arc: enable Android tracing in verified-boot mode

components/arc/trace/arc_trace_bridge.h

+// 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 COMPONENTS_ARC_TRACE_ARC_TRACE_BRIDGE_H_
+#define COMPONENTS_ARC_TRACE_ARC_TRACE_BRIDGE_H_
+
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "base/trace_event/trace_event.h"
+#include "components/arc/arc_bridge_service.h"
+#include "components/arc/arc_service.h"
+#include "components/arc/instance_holder.h"
+#include "mojo/public/cpp/bindings/binding.h"
+
+namespace arc {
+
+// This class provides the interface to trigger tracing in the container.
+class ArcTraceBridge : public ArcService,
+                       public InstanceHolder<mojom::TraceInstance>::Observer,
+                       public mojom::TraceHost {
+ public:
+  // Gets the singleton of this class.
+  static ArcTraceBridge* Get();
+
+  explicit ArcTraceBridge(ArcBridgeService* bridge_service);
+  ~ArcTraceBridge() override;
+
+  // Callback when the bridge is ready.
+  void OnInstanceReady() override;
+
+  // Starts tracing in the container.
+  void StartTracing(const base::trace_event::TraceConfig& trace_config);
+
+  // Stops tracing in the container.
+  void StopTracing();
+
+ private:
+  mojo::Binding<mojom::TraceHost> binding_;
+
+  base::WeakPtrFactory<ArcTraceBridge> weak_ptr_factory_;
+
+  base::ThreadChecker thread_checker_;
+
+  // List of available categories name. Each item is a pair of string. The
+  // first string is the category name, and the second string is the full name
+  // shown in the trace menu UI.
+  std::vector<std::pair<std::string, std::string>> categories_;

[Luis Héctor Chávez, 2016/10/11 13:13:03]

can you create a struct to hold both strings? that'll require less explanation.

[shunhsingou, 2016/10/12 04:24:26]

Done.

+
+  // Query the available categories for tracing.
+  void QueryAvailableCategories();
+
+  // Callback for QueryAvailableCategories.
+  void OnCategoriesReady(mojo::Array<mojo::String> categories);
+
+  // Callback for StartTracing.
+  void OnTraceStart(bool success);
+
+  // Callback for StopTracing.
+  void OnTraceStop(bool success);
+
+  DISALLOW_COPY_AND_ASSIGN(ArcTraceBridge);
+};
+
+}  // namespace arc
+
+#endif  // COMPONENTS_ARC_TRACE_ARC_TRACE_BRIDGE_H_