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

remoting/host/chromoting_host.cc

Index: remoting/host/chromoting_host.cc
diff --git a/remoting/host/chromoting_host.cc b/remoting/host/chromoting_host.cc
index dc509fe11bd07c3488aae18a99c5e85648af464b..b3cc0c326c366b066c66d00ffe77a1a375fb5a08 100644
--- a/remoting/host/chromoting_host.cc
+++ b/remoting/host/chromoting_host.cc
@@ -15,6 +15,7 @@
 #include "base/memory/ptr_util.h"
 #include "build/build_config.h"
 #include "jingle/glue/thread_wrapper.h"
+#include "remoting/base/auto_thread_task_runner.h"
 #include "remoting/base/constants.h"
 #include "remoting/base/logging.h"
 #include "remoting/host/chromoting_host_context.h"
@@ -67,13 +68,11 @@ ChromotingHost::ChromotingHost(
     DesktopEnvironmentFactory* desktop_environment_factory,
     std::unique_ptr<protocol::SessionManager> session_manager,
     scoped_refptr<protocol::TransportContext> transport_context,
-    scoped_refptr<base::SingleThreadTaskRunner> audio_task_runner,
-    scoped_refptr<base::SingleThreadTaskRunner> video_encode_task_runner)
+    const ChromotingHostContext& context)
     : desktop_environment_factory_(desktop_environment_factory),
       session_manager_(std::move(session_manager)),
       transport_context_(transport_context),
-      audio_task_runner_(audio_task_runner),
-      video_encode_task_runner_(video_encode_task_runner),
+      context_(context.Copy()),
       started_(false),
       login_backoff_(&kDefaultBackoffPolicy),
       enable_curtaining_(false),
@@ -268,16 +267,16 @@ void ChromotingHost::OnIncomingSession(
       protocol::SessionConfig::Protocol::WEBRTC) {
     connection.reset(new protocol::WebrtcConnectionToClient(
         base::WrapUnique(session), transport_context_,
-        video_encode_task_runner_));
+        context_->video_encode_task_runner()));
   } else {
     connection.reset(new protocol::IceConnectionToClient(
         base::WrapUnique(session), transport_context_,
-        video_encode_task_runner_));
+        context_->video_encode_task_runner()));
   }
 
   // Create a ClientSession object.
   ClientSession* client =
-      new ClientSession(this, audio_task_runner_, std::move(connection),
+      new ClientSession(*context_, this, std::move(connection),
                         desktop_environment_factory_, max_session_duration_,
                         pairing_registry_, extensions_.get());