Prepare SyntheticPointerAction to handle touch actions for multiple fingers

content/browser/renderer_host/input/synthetic_gesture_controller.h

Index: content/browser/renderer_host/input/synthetic_gesture_controller.h
diff --git a/content/browser/renderer_host/input/synthetic_gesture_controller.h b/content/browser/renderer_host/input/synthetic_gesture_controller.h
index f7b03c2fd795159b0a8dad61a6dee8965a4de6e7..9ef6829228c370a5545243834a8a36095ca967c3 100644
--- a/content/browser/renderer_host/input/synthetic_gesture_controller.h
+++ b/content/browser/renderer_host/input/synthetic_gesture_controller.h
@@ -43,6 +43,9 @@ class CONTENT_EXPORT SyntheticGestureController {
   // fully flushed from the input pipeline (i.e., sent, processed and ack'ed).
   void OnDidFlushInput();
 
+  SyntheticGestureParams::GestureSourceType
+  GetDefaultSyntheticGestureSourceType();
+
  private:
   void StartGesture(const SyntheticGesture& gesture);
   void StopGesture(const SyntheticGesture& gesture,