Prepare SyntheticPointerAction to handle touch actions for multiple fingers

content/browser/renderer_host/input/synthetic_gesture_controller.cc

Index: content/browser/renderer_host/input/synthetic_gesture_controller.cc
diff --git a/content/browser/renderer_host/input/synthetic_gesture_controller.cc b/content/browser/renderer_host/input/synthetic_gesture_controller.cc
index 109ce3465bd16de28e3f1e9d39da08106d285ede..81050166ae4e6085abc75efb6a19aef84702c52d 100644
--- a/content/browser/renderer_host/input/synthetic_gesture_controller.cc
+++ b/content/browser/renderer_host/input/synthetic_gesture_controller.cc
@@ -35,6 +35,8 @@ void SyntheticGestureController::QueueSyntheticGesture(
 }
 
 void SyntheticGestureController::Flush(base::TimeTicks timestamp) {
+  LOG(ERROR) << "SyntheticGestureController::Flush "
+             << pending_gesture_queue_.IsEmpty();
   TRACE_EVENT0("input", "SyntheticGestureController::Flush");
   if (pending_gesture_queue_.IsEmpty())
     return;
@@ -93,6 +95,11 @@ void SyntheticGestureController::StopGesture(
   completion_callback.Run(result);
 }
 
+SyntheticGestureParams::GestureSourceType
+SyntheticGestureController::GetDefaultSyntheticGestureSourceType() {
+  return gesture_target_->GetDefaultSyntheticGestureSourceType();
+}
+
 SyntheticGestureController::GestureAndCallbackQueue::GestureAndCallbackQueue() {
 }