[Chromoting] Use device::PowerSaveBlocker to block screen saver

remoting/host/host_power_save_blocker.cc

Index: remoting/host/host_power_save_blocker.cc
diff --git a/remoting/host/host_power_save_blocker.cc b/remoting/host/host_power_save_blocker.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c93f71c74e3bc94d2add624106ef341eb9794fa8
--- /dev/null
+++ b/remoting/host/host_power_save_blocker.cc
@@ -0,0 +1,45 @@
+// 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 "remoting/host/host_power_save_blocker.h"
+
+#include <utility>
+
+#include "base/logging.h"
+#include "base/single_thread_task_runner.h"
+#include "remoting/host/host_status_monitor.h"
+
+namespace remoting {
+
+HostPowerSaveBlocker::HostPowerSaveBlocker(
+    base::WeakPtr<HostStatusMonitor> monitor,
+    const scoped_refptr<base::SingleThreadTaskRunner>& ui_task_runner,
+    const scoped_refptr<base::SingleThreadTaskRunner>& file_task_runner)
+    : monitor_(monitor),
+      ui_task_runner_(ui_task_runner),
+      file_task_runner_(file_task_runner) {
+  DCHECK(monitor_);
+  monitor_->AddStatusObserver(this);
+}
+
+HostPowerSaveBlocker::~HostPowerSaveBlocker() {
+  if (monitor_.get()) {
+    monitor_->RemoveStatusObserver(this);
+  }
+}
+
+void HostPowerSaveBlocker::OnClientConnected(const std::string& jid) {
+  blocker_.reset(new device::PowerSaveBlocker(
+      device::PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep,
+      device::PowerSaveBlocker::kReasonOther,
+      "Remoting session is active",
+      ui_task_runner_,
+      file_task_runner_));
+}
+
+void HostPowerSaveBlocker::OnClientDisconnected(const std::string& jid) {
+  blocker_.reset();
+}
+
+}  // namespace remoting