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

remoting/host/chromoting_host_context.cc

Index: remoting/host/chromoting_host_context.cc
diff --git a/remoting/host/chromoting_host_context.cc b/remoting/host/chromoting_host_context.cc
index 8807af4f04d0e42d0fa19fe5b35538807ee13379..5919f86f3e1e5f0ffc62a0a85e08b49524809ec2 100644
--- a/remoting/host/chromoting_host_context.cc
+++ b/remoting/host/chromoting_host_context.cc
@@ -44,7 +44,7 @@ ChromotingHostContext::ChromotingHostContext(
 ChromotingHostContext::~ChromotingHostContext() {
 }
 
-std::unique_ptr<ChromotingHostContext> ChromotingHostContext::Copy() {
+std::unique_ptr<ChromotingHostContext> ChromotingHostContext::Copy() const {
   return base::WrapUnique(new ChromotingHostContext(
       ui_task_runner_, audio_task_runner_, file_task_runner_,
       input_task_runner_, network_task_runner_, video_capture_task_runner_,
@@ -115,15 +115,19 @@ std::unique_ptr<ChromotingHostContext> ChromotingHostContext::Create(
   network_task_runner->PostTask(FROM_HERE,
                                 base::Bind(&DisallowBlockingOperations));
 
-  return base::WrapUnique(new ChromotingHostContext(
-      ui_task_runner, audio_task_runner, file_task_runner,
+  return Create(ui_task_runner, audio_task_runner, file_task_runner,
       AutoThread::CreateWithType("ChromotingInputThread", ui_task_runner,
                                  base::MessageLoop::TYPE_IO),
       network_task_runner,
       AutoThread::Create("ChromotingCaptureThread", ui_task_runner),
-      AutoThread::Create("ChromotingEncodeThread", ui_task_runner),
-      make_scoped_refptr(
-          new URLRequestContextGetter(network_task_runner, file_task_runner))));
+      AutoThread::Create("ChromotingEncodeThread", ui_task_runner));
+}
+
+// static
+std::unique_ptr<ChromotingHostContext> ChromotingHostContext::CreateForTest(
+    scoped_refptr<AutoThreadTaskRunner> task_runner) {
+  return Create(task_runner, task_runner, task_runner, task_runner, task_runner,
+      task_runner, task_runner);
 }
 
 #if defined(OS_CHROMEOS)
@@ -164,4 +168,26 @@ std::unique_ptr<ChromotingHostContext> ChromotingHostContext::CreateForChromeOS(
 }
 #endif  // defined(OS_CHROMEOS)
 
+// static
+std::unique_ptr<ChromotingHostContext> ChromotingHostContext::Create(
+      scoped_refptr<AutoThreadTaskRunner> ui_task_runner,
+      scoped_refptr<AutoThreadTaskRunner> audio_task_runner,
+      scoped_refptr<AutoThreadTaskRunner> file_task_runner,
+      scoped_refptr<AutoThreadTaskRunner> input_task_runner,
+      scoped_refptr<AutoThreadTaskRunner> network_task_runner,
+      scoped_refptr<AutoThreadTaskRunner> video_capture_task_runner,
+      scoped_refptr<AutoThreadTaskRunner> video_encode_task_runner) {
+  if (ui_task_runner && audio_task_runner && file_task_runner &&
+      input_task_runner && network_task_runner && video_capture_task_runner &&
+      video_encode_task_runner) {
+  return base::WrapUnique(new ChromotingHostContext(
+      ui_task_runner, audio_task_runner, file_task_runner, input_task_runner,
+      network_task_runner, video_capture_task_runner, video_encode_task_runner,
+      make_scoped_refptr(
+          new URLRequestContextGetter(network_task_runner, file_task_runner))));
+
+  }
+  return std::unique_ptr<ChromotingHostContext>();
+}
+
 }  // namespace remoting