BT adapter is switched to initial state after HID screen if no BT devices connected.

chrome/browser/ui/webui/chromeos/login/hid_detection_screen_handler.cc

Index: chrome/browser/ui/webui/chromeos/login/hid_detection_screen_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/hid_detection_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/hid_detection_screen_handler.cc
index fd49f5bc4ed59c8e7c35fdc48f4cc8acd9d8a05d..c57556b30fc3683267cbf9d00a087d118f2555f2 100644
--- a/chrome/browser/ui/webui/chromeos/login/hid_detection_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/hid_detection_screen_handler.cc
@@ -73,12 +73,15 @@ HIDDetectionScreenHandler::HIDDetectionScreenHandler(
       core_oobe_actor_(core_oobe_actor),
       show_on_init_(false),
       mouse_is_pairing_(false),
+      pointing_device_connect_type_(InputDeviceInfo::TYPE_UNKNOWN),
       keyboard_is_pairing_(false),
+      keyboard_device_connect_type_(InputDeviceInfo::TYPE_UNKNOWN),
       switch_on_adapter_when_ready_(false),
       weak_ptr_factory_(this) {
 }
 
 HIDDetectionScreenHandler::~HIDDetectionScreenHandler() {
+  adapter_initially_powered_.reset();
   if (adapter_.get())
     adapter_->RemoveObserver(this);
   input_service_proxy_.RemoveObserver(this);
@@ -97,6 +100,10 @@ void HIDDetectionScreenHandler::SetPoweredError() {
   LOG(ERROR) << "Failed to power BT adapter";
 }
 
+void HIDDetectionScreenHandler::SetPoweredOffError() {
+  LOG(ERROR) << "Failed to power off BT adapter";
+}
+
 void HIDDetectionScreenHandler::FindDevicesError() {
   VLOG(1) << "Failed to start Bluetooth discovery.";
 }
@@ -196,6 +203,20 @@ void HIDDetectionScreenHandler::HandleOnContinue() {
       scenario_type,
       CONTINUE_SCENARIO_TYPE_SIZE);
 
+  // Switch off BT adapter if it was off before the screen and no BT device
+  // connected.
+  if (adapter_ && adapter_->IsPresent() && adapter_->IsPowered() &&
+      !(pointing_device_connect_type_ == InputDeviceInfo::TYPE_BLUETOOTH ||
+        keyboard_device_connect_type_ == InputDeviceInfo::TYPE_BLUETOOTH) &&
+      adapter_initially_powered_ && !(*adapter_initially_powered_.get())) {

[Nikita (slow), 2014/08/07 14:47:28]

nit: you don't need to .get(), just 

!*adapter_initially_powered_

+    VLOG(1) << "Switching off BT adapter after HID OOBE screen as unused.";
+    adapter_->SetPowered(
+        false,
+        base::Bind(&base::DoNothing),
+        base::Bind(&HIDDetectionScreenHandler::SetPoweredOffError,
+                   weak_ptr_factory_.GetWeakPtr()));
+  }
+
   core_oobe_actor_->StopDemoModeDetection();
   if (delegate_)
     delegate_->OnExit();
@@ -286,6 +307,8 @@ void HIDDetectionScreenHandler::AuthorizePairing(
 void HIDDetectionScreenHandler::AdapterPresentChanged(
     device::BluetoothAdapter* adapter, bool present) {
   if (present && switch_on_adapter_when_ready_) {
+    VLOG(1) << "Switching on BT adapter on HID OOBE screen.";
+    adapter_initially_powered_.reset(new bool(adapter_->IsPowered()));
     adapter_->SetPowered(
         true,
         base::Bind(&HIDDetectionScreenHandler::StartBTDiscoverySession,
@@ -430,6 +453,8 @@ void HIDDetectionScreenHandler::TryInitiateBTDevicesUpdate() {
       // Switch on BT adapter later when it's available.
       switch_on_adapter_when_ready_ = true;
     } else if (!adapter_->IsPowered()) {
+      VLOG(1) << "Switching on BT adapter on HID OOBE screen.";
+      adapter_initially_powered_.reset(new bool(false));
       adapter_->SetPowered(
           true,
           base::Bind(&HIDDetectionScreenHandler::StartBTDiscoverySession,