Added system log uploader.

chrome/browser/chromeos/policy/system_log_uploader.cc

+// Copyright (c) 2015 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 "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/location.h"
+#include "chrome/browser/chromeos/policy/system_log_uploader.h"
+
+namespace {
+// Determines the time between log uploads.
+const int64 kDefaultUploadDelayMs = 12 * 60 * 60 * 1000;  // 12 hours
+
+// Determines the time, measured from the time of last failed upload,
+// after which the log upload is retried.
+const int64 kErrorUploadDelayMs = 120 * 1000;  // 120 seconds
+
+}  // namespace
+
+namespace policy {
+
+SystemLogUploader::SystemLogUploader(
+    const scoped_refptr<base::SequencedTaskRunner>& task_runner,
+    scoped_ptr<SystemLogUploadJob> upload_job)
+    : last_success_(true),
+      upload_frequency_(
+          base::TimeDelta::FromMilliseconds(kDefaultUploadDelayMs)),
+      last_upload_(base::Time::NowFromSystemTime()),
+      task_runner_(task_runner),
+      upload_job_(upload_job.Pass()),
+      weak_factory_(this) {
+  DCHECK(upload_job_);
+  // Immediately schedule the next system log upload after upload_frequency_
+  // time from now.
+  ScheduleNextSystemLogUpload(upload_frequency_);
+}
+
+SystemLogUploader::~SystemLogUploader() {
+}
+
+void SystemLogUploader::OnSuccess() {
+  // On successful log upload schedule next log upload after upload_frequency_
+  // time from now.
+  last_success_ = true;
+  last_upload_ = base::Time::NowFromSystemTime();
+
+  upload_job_->Terminate();
+  ScheduleNextSystemLogUpload(upload_frequency_);
+}
+
+void SystemLogUploader::OnFailure() {
+  // On first failure log upload try to re-upload logs after kErrorUploadDelayMs
+  // time from now.
+  last_upload_ = base::Time::NowFromSystemTime();
+
+  upload_job_->Terminate();
+  if (last_success_)
+    ScheduleNextSystemLogUpload(

[Andrew T Wilson (Slow), 2015/06/29 15:06:09]

You have a multiple line statement here, so you have to put curly braces for
this if statement.

i.e. this is OK

if (foo)
  do_foo()
else
  do_bar()

But this is not OK:

if (foo)
  do_foo(
    long_line_of_wrapped_params)
else
  do_bar()

You have to do this:

if (foo) {
  do_foo(
    long_line_of_params)
} else {
  do_bar()
}

[Polina Bondarenko, 2015/07/02 15:28:04]

Done.

+        base::TimeDelta::FromMilliseconds(kErrorUploadDelayMs));
+  else
+    ScheduleNextSystemLogUpload(upload_frequency_);
+
+  last_success_ = !last_success_;

[Andrew T Wilson (Slow), 2015/06/29 15:06:09]

This logic works, but I think it'd be easier to read if you just had a retrying_
flag instead of last_success_.

[Polina Bondarenko, 2015/07/02 15:28:04]

Done.

+}
+
+void SystemLogUploader::StartLogUpload() {
+  upload_job_->Run(
+      base::Bind(&SystemLogUploader::OnSuccess, base::Unretained(this)),

[Andrew T Wilson (Slow), 2015/06/29 15:06:09]

Why use base::Unretained() here? Why do you have a weak_ptr_factory?

[Polina Bondarenko, 2015/07/02 15:28:04]

Understood, changed to weak_factory_ to prevent failures.

+      base::Bind(&SystemLogUploader::OnFailure, base::Unretained(this)));
+}
+void SystemLogUploader::ScheduleNextSystemLogUpload(base::TimeDelta frequency) {

[Andrew T Wilson (Slow), 2015/06/29 15:06:09]

nit: blank line between methods

[Polina Bondarenko, 2015/07/02 15:28:04]

Done.

+  // Calculate when to fire off the next update.
+  base::TimeDelta delay =
+      std::max((last_upload_ + frequency) - base::Time::NowFromSystemTime(),
+               base::TimeDelta());
+  task_runner_->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&SystemLogUploader::StartLogUpload, base::Unretained(this)),

[Andrew T Wilson (Slow), 2015/06/29 15:06:09]

Should use weak_ptr_factory instead of base::unretained()

[Polina Bondarenko, 2015/07/02 15:28:04]

Done.

+      delay);
+}
+
+}  // namespace policy