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

remoting/host/client_session.cc

Index: remoting/host/client_session.cc
diff --git a/remoting/host/client_session.cc b/remoting/host/client_session.cc
index 99c7ed509963a449f2a799cf36e044f4d7cbe00c..432ab211fa320e07ebd1b069c0017462cb4be7c1 100644
--- a/remoting/host/client_session.cc
+++ b/remoting/host/client_session.cc
@@ -12,6 +12,7 @@
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
+#include "remoting/base/auto_thread_task_runner.h"
 #include "remoting/base/capabilities.h"
 #include "remoting/base/constants.h"
 #include "remoting/base/logging.h"
@@ -60,8 +61,8 @@ std::unique_ptr<AudioEncoder> CreateAudioEncoder(
 }  // namespace
 
 ClientSession::ClientSession(
+    const ChromotingHostContext& context,
     EventHandler* event_handler,
-    scoped_refptr<base::SingleThreadTaskRunner> audio_task_runner,
     std::unique_ptr<protocol::ConnectionToClient> connection,
     DesktopEnvironmentFactory* desktop_environment_factory,
     const base::TimeDelta& max_duration,
@@ -78,12 +79,18 @@ ClientSession::ClientSession(
       disable_clipboard_filter_(clipboard_echo_filter_.host_filter()),
       client_clipboard_factory_(clipboard_echo_filter_.client_filter()),
       max_duration_(max_duration),
-      audio_task_runner_(audio_task_runner),
+      audio_task_runner_(context.audio_task_runner()),
       pairing_registry_(pairing_registry),
       // Note that |lossless_video_color_| defaults to true, but actually only
       // controls VP9 video stream color quality.
       lossless_video_color_(!base::CommandLine::ForCurrentProcess()->HasSwitch(
           kDisableI444SwitchName)),
+      power_save_blocker_(
+          device::PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep,
+          device::PowerSaveBlocker::kReasonVideoPlayback,
+          "Remoting session is active",
+          context.ui_task_runner(),
+          context.file_task_runner()),
       weak_factory_(this) {
   connection_->SetEventHandler(this);