Allow scrolling a page with selection after long-press on whitespace

ui/touch_selection/touch_selection_controller.cc

Index: ui/touch_selection/touch_selection_controller.cc
diff --git a/ui/touch_selection/touch_selection_controller.cc b/ui/touch_selection/touch_selection_controller.cc
index 90f7c6241580f66532ff678d360f070a8fa82bc3..35cdf1af190be4e4d738eda373e0f7c5ae37c9b2 100644
--- a/ui/touch_selection/touch_selection_controller.cc
+++ b/ui/touch_selection/touch_selection_controller.cc
@@ -231,6 +231,15 @@ bool TouchSelectionController::WillHandleLongPressEvent(
   return false;
 }
 
+void TouchSelectionController::OnScrollBeginEvent() {
+  longpress_drag_selector_.OnScrollBeginEvent();
+  response_pending_input_event_ = INPUT_EVENT_TYPE_NONE;
+  if (active_status_ == INACTIVE) {
+    activate_insertion_automatically_ = false;
+    activate_selection_automatically_ = false;
+  }
+}
+
 void TouchSelectionController::AllowShowingFromCurrentSelection() {
   if (active_status_ != INACTIVE)
     return;