arc: enable Android tracing in verified-boot mode

components/arc/trace/arc_trace_bridge.cc

+// 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.
+
+#include "components/arc/trace/arc_trace_bridge.h"
+
+#include <string>
+#include <utility>
+
+#include "base/logging.h"
+#include "base/trace_event/trace_event.h"
+#include "components/arc/arc_bridge_service.h"
+
+namespace arc {
+
+namespace {
+// This class is owned by ArcServiceManager so that it is safe to use this raw
+// pointer as the singleton reference.
+ArcTraceBridge* g_arc_trace_bridge = nullptr;
+
+// The prefix of the categories to be shown on the trace selection UI.
+constexpr char kCategoryPrefix[] = TRACE_DISABLED_BY_DEFAULT("android ");
+
+}  // namcespace
+
+ArcTraceBridge* ArcTraceBridge::Get() {
+  DCHECK(g_arc_trace_bridge);
+  return g_arc_trace_bridge;
+}
+
+ArcTraceBridge::ArcTraceBridge(ArcBridgeService* bridge_service)
+    : ArcService(bridge_service), binding_(this), weak_ptr_factory_(this) {
+  arc_bridge_service()->trace()->AddObserver(this);
+  g_arc_trace_bridge = this;
+}
+
+ArcTraceBridge::~ArcTraceBridge() {
+  arc_bridge_service()->trace()->RemoveObserver(this);
+  g_arc_trace_bridge = nullptr;
+}
+
+void ArcTraceBridge::OnInstanceReady() {
+  QueryAvailableCategories();
+}
+
+void ArcTraceBridge::QueryAvailableCategories() {
+  auto* trace_instance = arc_bridge_service()->trace()->GetInstanceForMethod(
+      "QueryAvailableCategories");
+  if (!trace_instance)
+    return;
+  trace_instance->QueryAvailableCategories(base::Bind(
+      &ArcTraceBridge::OnCategoriesReady, weak_ptr_factory_.GetWeakPtr()));
+}
+
+void ArcTraceBridge::OnCategoriesReady(mojo::Array<mojo::String> categories) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  for (const auto& category : categories) {
+    categories_.push_back(std::pair<std::string, std::string>(
+        category, std::string(kCategoryPrefix) + std::string(category)));
+    // Shows the category name in the selection UI.
+    base::trace_event::TraceLog::GetCategoryGroupEnabled(
+        categories_.back().second.c_str());
+  }
+}
+
+void ArcTraceBridge::StartTracing(
+    const base::trace_event::TraceConfig& trace_config) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto* trace_instance =
+      arc_bridge_service()->trace()->GetInstanceForMethod("StartTracing");
+  if (!trace_instance)
+    return;
+
+  mojo::Array<mojo::String> selected_categories;
+  for (const auto& category : categories_) {
+    if (trace_config.IsCategoryGroupEnabled(category.second.c_str())) {
+      selected_categories.push_back(category.first);
+    }
+  }
+
+  trace_instance->StartTracing(std::move(selected_categories),
+                               base::Bind(&ArcTraceBridge::OnTraceStart,
+                                          weak_ptr_factory_.GetWeakPtr()));
+}
+
+void ArcTraceBridge::StopTracing() {
+  auto* trace_instance =
+      arc_bridge_service()->trace()->GetInstanceForMethod("StopTracing");
+  if (!trace_instance)
+    return;
+  trace_instance->StopTracing(
+      base::Bind(&ArcTraceBridge::OnTraceStop, weak_ptr_factory_.GetWeakPtr()));
+}
+
+void ArcTraceBridge::OnTraceStart(bool success) {
+  if (!success) {

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

nit: elide braces if both the condition and the block fit on a single line.

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

Done.

+    LOG(ERROR) << "Failed to start tracing in the container.";
+  }
+}
+
+void ArcTraceBridge::OnTraceStop(bool success) {
+  if (!success) {
+    LOG(ERROR) << "Failed to stop tracing in the container.";
+  }
+}
+
+}  // namespace arc