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

device/usb/usb_service_android.h

Index: device/usb/usb_service_android.h
diff --git a/device/usb/usb_service_android.h b/device/usb/usb_service_android.h
index 6fef48f9bc71a6c573c1b04c325a2b61e6b3c910..ae1ec5a3f2269ec9435feb283ddf94f4c269744e 100644
--- a/device/usb/usb_service_android.h
+++ b/device/usb/usb_service_android.h
@@ -5,21 +5,19 @@
 #ifndef DEVICE_USB_USB_SERVICE_ANDROID_H_
 #define DEVICE_USB_USB_SERVICE_ANDROID_H_
 
-#include <string>
+#include <jni.h>
+
 #include <unordered_map>
 
 #include "base/android/scoped_java_ref.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
-#include "device/usb/usb_device_android.h"
 #include "device/usb/usb_service.h"
 
-namespace base {
-class SequencedTaskRunner;
-}
-
 namespace device {
 
+class UsbDeviceAndroid;
+
 // USB service implementation for Android. This is a stub implementation that
 // does not return any devices.
 class UsbServiceAndroid : public UsbService {
@@ -27,8 +25,7 @@ class UsbServiceAndroid : public UsbService {
   // Register C++ methods exposed to Java using JNI.
   static bool RegisterJNI(JNIEnv* env);
 
-  UsbServiceAndroid(
-      scoped_refptr<base::SequencedTaskRunner> blocking_task_runner);
+  UsbServiceAndroid();
   ~UsbServiceAndroid() override;
 
   // Methods called by Java.