Use the task scheduler for blocking tasks in the USB service on Linux

device/usb/usb_service_linux.h

Index: device/usb/usb_service_linux.h
diff --git a/device/usb/usb_service_linux.h b/device/usb/usb_service_linux.h
index 02fcafcf9596651aadf2a1be42c944e592ec15e5..0b983ee0e36472c76d6f8dad3042051352547d43 100644
--- a/device/usb/usb_service_linux.h
+++ b/device/usb/usb_service_linux.h
@@ -10,10 +10,6 @@
 #include "base/memory/weak_ptr.h"
 #include "device/usb/usb_service.h"
 
-namespace base {
-class SequencedTaskRunner;
-}
-
 namespace device {
 
 struct UsbDeviceDescriptor;
@@ -21,8 +17,7 @@ class UsbDeviceLinux;
 
 class UsbServiceLinux : public UsbService {
  public:
-  explicit UsbServiceLinux(
-      scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_in);
+  UsbServiceLinux();
   ~UsbServiceLinux() override;
 
   // device::UsbService implementation