Adds a callback to TracingAgent::StartAgentTracing()

chromeos/dbus/debug_daemon_client.cc

 // Copyright (c) 2012 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 "chromeos/dbus/debug_daemon_client.h"
 
 #include <fcntl.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <unistd.h>
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/files/file_path.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/strings/string_util.h"
 #include "base/task_runner_util.h"
+#include "base/thread_task_runner_handle.h"
 #include "chromeos/dbus/pipe_reader.h"
 #include "dbus/bus.h"
 #include "dbus/message.h"
 #include "dbus/object_path.h"
 #include "dbus/object_proxy.h"
 
 namespace {
 
 const char kCrOSTracingAgentName[] = "cros";
 const char kCrOSTraceLabel[] = "systemTraceEvents";
@@ skipping 166 matching lines @@
         base::Bind(&DebugDaemonClientImpl::OnGetUserLogFiles,
                    weak_ptr_factory_.GetWeakPtr(),
                    callback));
   }
 
   // base::trace_event::TracingAgent implementation.
   std::string GetTracingAgentName() override { return kCrOSTracingAgentName; }
 
   std::string GetTraceEventLabel() override { return kCrOSTraceLabel; }
 
-  bool StartAgentTracing(
-      const base::trace_event::TraceConfig& trace_config) override {
+  void StartAgentTracing(const base::trace_event::TraceConfig& trace_config,
+                         const StartAgentTracingCallback& callback) override {
     dbus::MethodCall method_call(
         debugd::kDebugdInterface,
         debugd::kSystraceStart);
     dbus::MessageWriter writer(&method_call);
     writer.AppendString("all"); // TODO(sleffler) parameterize category list
 
     DVLOG(1) << "Requesting a systrace start";
     debugdaemon_proxy_->CallMethod(
         &method_call,
         dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
         base::Bind(&DebugDaemonClientImpl::OnStartMethod,
                    weak_ptr_factory_.GetWeakPtr()));
-    return true;
+
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::Bind(callback, GetTracingAgentName(), true));

[stevenjb, 2016/01/26 20:11:19]

Document |success|, i.e: true /* success */

[charliea (OOO until 10-5), 2016/01/26 20:29:56]

Ah, didn't know that you were supposed to do this. Done.

   }
 
   void StopAgentTracing(const StopAgentTracingCallback& callback) override {
     DCHECK(stop_agent_tracing_task_runner_);
     if (pipe_reader_ != NULL) {
       LOG(ERROR) << "Busy doing StopSystemTracing";
       return;
     }
 
     pipe_reader_.reset(
@@ skipping 407 matching lines @@
 DebugDaemonClient::EmptyStopAgentTracingCallback() {
   return base::Bind(&EmptyStopAgentTracingCallbackBody);
 }
 
 // static
 DebugDaemonClient* DebugDaemonClient::Create() {
   return new DebugDaemonClientImpl();
 }
 
 }  // namespace chromeos