Add GetLog method call to DebugDaemonClient

chromeos/dbus/debug_daemon_client.cc

Index: chromeos/dbus/debug_daemon_client.cc
diff --git a/chromeos/dbus/debug_daemon_client.cc b/chromeos/dbus/debug_daemon_client.cc
index 955e26a5a3e003598aeb3fcd438f25d95628a54b..35842a83b991b35d38c3ae2ea9a7ebb2512a4332 100644
--- a/chromeos/dbus/debug_daemon_client.cc
+++ b/chromeos/dbus/debug_daemon_client.cc
@@ -281,6 +281,16 @@ class DebugDaemonClientImpl : public DebugDaemonClient {
                    callback));
   }
 
+  void GetLog(const std::string& log_name,
+              const GetLogsCallback& callback) override {
+    dbus::MethodCall method_call(debugd::kDebugdInterface, debugd::kGetLog);
+    dbus::MessageWriter(&method_call).AppendString(log_name);
+    debugdaemon_proxy_->CallMethod(
+        &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+        base::Bind(&DebugDaemonClientImpl::OnGetLog,
+                   weak_ptr_factory_.GetWeakPtr(), log_name, callback));
+  }
+
   // base::trace_event::TracingAgent implementation.
   std::string GetTracingAgentName() override { return kCrOSTracingAgentName; }
 
@@ -629,6 +639,19 @@ class DebugDaemonClientImpl : public DebugDaemonClient {
     return OnGetAllLogs(callback, response);
   }
 
+  void OnGetLog(const std::string& log_name,
+                const GetLogsCallback& callback,
+                dbus::Response* response) {
+    std::map<std::string, std::string> result;
+    std::string result_string;
+    if (!response || !dbus::MessageReader(response).PopString(&result_string)) {
+      callback.Run(false, result);
+      return;
+    }
+    result[log_name] = result_string;

[Daniel Erat, 2017/06/23 01:04:27]

returning a single-entry map feels a bit hacky. would it make sense to add a new
GetLogCallback typedef that just receives a string?

[Simon Que, 2017/06/23 01:15:10]

Done.

+    callback.Run(true, result);
+  }
+
   void OnBigFeedbackLogsResponse(base::WeakPtr<PipeReaderWrapper> pipe_reader,
                                  dbus::Response* response) {
     if (!response && pipe_reader.get()) {