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

ui/touch_selection/longpress_drag_selector.cc

Index: ui/touch_selection/longpress_drag_selector.cc
diff --git a/ui/touch_selection/longpress_drag_selector.cc b/ui/touch_selection/longpress_drag_selector.cc
index b84c90da9e137cc9f5c068ae75941aa8aaededa6..fdc3221118a87a41803686afb13042c5beae7b07 100644
--- a/ui/touch_selection/longpress_drag_selector.cc
+++ b/ui/touch_selection/longpress_drag_selector.cc
@@ -108,7 +108,7 @@ bool LongPressDragSelector::WillHandleTouchEvent(const MotionEvent& event) {
 }
 
 bool LongPressDragSelector::IsActive() const {
-  return state_ != INACTIVE && state_ != LONGPRESS_PENDING;
+  return state_ == DRAG_PENDING || state_ == DRAGGING;
 }
 
 void LongPressDragSelector::OnLongPressEvent(base::TimeTicks event_time,
@@ -126,6 +126,10 @@ void LongPressDragSelector::OnLongPressEvent(base::TimeTicks event_time,
   }
 }
 
+void LongPressDragSelector::OnScrollBeginEvent() {
+  SetState(INACTIVE);
+}
+
 void LongPressDragSelector::OnSelectionActivated() {
   if (state_ == SELECTION_PENDING)
     SetState(DRAG_PENDING);