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

device/usb/usb_device_android.h

Index: device/usb/usb_device_android.h
diff --git a/device/usb/usb_device_android.h b/device/usb/usb_device_android.h
index 699354e9f7bff852b322c5176783da9e69fe58f1..542052dac6d58ee83991c45de154da81bdb2627e 100644
--- a/device/usb/usb_device_android.h
+++ b/device/usb/usb_device_android.h
@@ -9,10 +9,6 @@
 #include "base/memory/weak_ptr.h"
 #include "device/usb/usb_device.h"
 
-namespace base {
-class SequencedTaskRunner;
-}
-
 namespace device {
 
 class UsbServiceAndroid;
@@ -22,7 +18,6 @@ class UsbDeviceAndroid : public UsbDevice {
   static scoped_refptr<UsbDeviceAndroid> Create(
       JNIEnv* env,
       base::WeakPtr<UsbServiceAndroid> service,
-      scoped_refptr<base::SequencedTaskRunner> blocking_task_runner,
       const base::android::JavaRef<jobject>& usb_device);
 
   // UsbDevice:
@@ -47,7 +42,6 @@ class UsbDeviceAndroid : public UsbDevice {
       const base::string16& manufacturer_string,
       const base::string16& product_string,
       const base::string16& serial_number,
-      scoped_refptr<base::SequencedTaskRunner> blocking_task_runner,
       const base::android::JavaRef<jobject>& wrapper);
   ~UsbDeviceAndroid() override;
 
@@ -61,8 +55,6 @@ class UsbDeviceAndroid : public UsbDevice {
       std::unique_ptr<WebUsbAllowedOrigins> allowed_origins,
       const GURL& landing_page);
 
-  scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
-
   const jint device_id_;
   bool permission_granted_ = false;
   std::list<ResultCallback> request_permission_callbacks_;