cros: Move TrayBluetoothHelper out of chrome into ash

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index 94ded5f1f8a09045934923ae9dee8db0786a3f8c..fa1c08d5417722bc7fe94bfe591c54ce235c2815 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -30,6 +30,7 @@
 #include "ash/common/shell_delegate.h"
 #include "ash/common/shell_observer.h"
 #include "ash/common/system/chromeos/bluetooth/bluetooth_notification_controller.h"
+#include "ash/common/system/chromeos/bluetooth/tray_bluetooth_helper.h"
 #include "ash/common/system/chromeos/network/sms_observer.h"
 #include "ash/common/system/chromeos/power/power_status.h"
 #include "ash/common/system/status_area_widget.h"
@@ -590,6 +591,7 @@ Shell::~Shell() {
   // to deinitialize the shelf first, as it is initialized after the delegate.
   for (WmWindow* root : wm_shell_->GetAllRootWindows())
     root->GetRootWindowController()->GetShelf()->ShutdownShelfWidget();
+  tray_bluetooth_helper_.reset();

[James Cook, 2017/03/20 23:27:09]

The timing of bluetooth adapter init/shutdown is not 100% clear to me, so I'm
keeping the timing as close as possible to what it was before.

[msw, 2017/03/20 23:47:07]

Acknowledged.

   wm_shell_->DeleteSystemTrayDelegate();
 
   // Drag-and-drop must be canceled prior to close all windows.
@@ -954,6 +956,9 @@ void Shell::Init(const ShellInitParams& init_params) {
   wm_shell_->SetSystemTrayDelegate(
       base::WrapUnique(shell_delegate_->CreateSystemTrayDelegate()));
 
+  tray_bluetooth_helper_ = base::MakeUnique<TrayBluetoothHelper>();
+  tray_bluetooth_helper_->Initialize();

[msw, 2017/03/20 23:47:07]

Can we move instantiation to the ctor, or combine construction and init?

[James Cook, 2017/03/21 00:18:08]

Moved instantiation to the ctor.

+
   // Create AshTouchTransformController before
   // WindowTreeHostManager::InitDisplays()
   // since AshTouchTransformController listens on