Add GetLog method call to DebugDaemonClient

This gets an individual log from debugd.

BUG=733846

Review-Url: https://codereview.chromium.org/2944403002
Cr-Commit-Position: refs/heads/master@{#481805}

chromeos/dbus/debug_daemon_client.cc

@@ -281,6 +281,16 @@ class DebugDaemonClientImpl : public DebugDaemonClient {
                    callback));
   }
 
+  void GetLog(const std::string& log_name,
+              const GetLogCallback& 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 +639,17 @@ class DebugDaemonClientImpl : public DebugDaemonClient {
     return OnGetAllLogs(callback, response);
   }
 
+  void OnGetLog(const std::string& log_name,
+                const GetLogCallback& callback,
+                dbus::Response* response) {
+    std::string result;
+    if (!response || !dbus::MessageReader(response).PopString(&result)) {
+      callback.Run(false, result);
+      return;
+    }
+    callback.Run(true, result);
+  }
+
   void OnBigFeedbackLogsResponse(base::WeakPtr<PipeReaderWrapper> pipe_reader,
                                  dbus::Response* response) {
     if (!response && pipe_reader.get()) {

chromeos/dbus/debug_daemon_client.h

@@ -114,6 +114,9 @@ class CHROMEOS_EXPORT DebugDaemonClient
   using GetLogsCallback =
       base::Callback<void(bool succeeded,
                           const std::map<std::string, std::string>& logs)>;
+  // Callback type for GetLog().
+  using GetLogCallback =
+      base::Callback<void(bool succeeded, const std::string& result)>;
 
   // Gets scrubbed logs from debugd.
   virtual void GetScrubbedLogs(const GetLogsCallback& callback) = 0;
@@ -129,6 +132,10 @@ class CHROMEOS_EXPORT DebugDaemonClient
   // Gets list of user log files that must be read by Chrome.
   virtual void GetUserLogFiles(const GetLogsCallback& callback) = 0;
 
+  // Gets an individual log source provided by debugd.
+  virtual void GetLog(const std::string& log_name,
+                      const GetLogCallback& callback) = 0;
+
   virtual void SetStopAgentTracingTaskRunner(
       scoped_refptr<base::TaskRunner> task_runner) = 0;
 

chromeos/dbus/fake_debug_daemon_client.cc

@@ -143,6 +143,13 @@ void FakeDebugDaemonClient::GetUserLogFiles(const GetLogsCallback& callback) {
       FROM_HERE, base::Bind(callback, true, user_logs));
 }
 
+void FakeDebugDaemonClient::GetLog(const std::string& log_name,
+                                   const GetLogCallback& callback) {
+  std::string result = log_name + ": response from GetLog";
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::Bind(callback, true, result));
+}
+
 void FakeDebugDaemonClient::TestICMP(const std::string& ip_address,
                                      const TestICMPCallback& callback) {
   base::ThreadTaskRunnerHandle::Get()->PostTask(

chromeos/dbus/fake_debug_daemon_client.h

@@ -54,6 +54,8 @@ class CHROMEOS_EXPORT FakeDebugDaemonClient : public DebugDaemonClient {
   void GetScrubbedLogs(const GetLogsCallback& callback) override;
   void GetScrubbedBigLogs(const GetLogsCallback& callback) override;
   void GetAllLogs(const GetLogsCallback& callback) override;
+  void GetLog(const std::string& log_name,
+              const GetLogCallback& callback) override;
   void GetUserLogFiles(const GetLogsCallback& callback) override;
   void TestICMP(const std::string& ip_address,
                 const TestICMPCallback& callback) override;