overview: Factor out repeated code into helper function

Bug: None
Change-Id: I53fd720e73d6c68a9264cc153a65fea5ff3dba4d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2033631
Commit-Queue: Avery Musbach <amusbach@chromium.org>
Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#737516}

ash/wm/overview/overview_grid.cc

@@ -604,10 +604,8 @@ void OverviewGrid::RemoveItem(OverviewItem* overview_item,
     // update the grid bounds if the window being dragged from the top or shelf,
     // the former being handled in TabletModeWindowDragDelegate's destructor.
     base::flat_set<OverviewItem*> ignored_items;
-    if (overview_session_->window_drag_controller() &&
-        overview_session_->window_drag_controller()->item()) {
+    if (overview_session_->IsAnyOverviewItemDragged())
       ignored_items.insert(overview_session_->window_drag_controller()->item());
-    }
     const gfx::Rect grid_bounds = GetGridBoundsInScreen(
         root_window_,
         split_view_drag_indicators_

ash/wm/overview/overview_item.cc

@@ -1306,10 +1306,8 @@ void OverviewItem::HandlePressEvent(const gfx::PointF& location_in_screen,
                                     bool from_touch_gesture) {
   // We allow switching finger while dragging, but do not allow dragging two
   // or more items.
-  if (overview_session_->window_drag_controller() &&
-      overview_session_->window_drag_controller()->item()) {
+  if (overview_session_->IsAnyOverviewItemDragged())
     return;
-  }
 
   StartDrag();
   overview_session_->InitiateDrag(this, location_in_screen,

ash/wm/overview/overview_session.cc

@@ -271,6 +271,10 @@ void OverviewSession::Shutdown() {
   }
 }
 
+bool OverviewSession::IsAnyOverviewItemDragged() const {
+  return window_drag_controller_ && window_drag_controller_->item();
+}
+
 void OverviewSession::OnGridEmpty() {
   if (!IsEmpty())
     return;
@@ -1021,7 +1025,7 @@ void OverviewSession::OnSplitViewDividerPositionChanged() {
 
 void OverviewSession::Move(bool reverse) {
   // Do not allow moving the highlight while in the middle of a drag.
-  if (window_drag_controller_ && window_drag_controller_->item())
+  if (IsAnyOverviewItemDragged())
     return;
 
   highlight_controller_->MoveHighlight(reverse);

ash/wm/overview/overview_session.h

@@ -120,6 +120,8 @@ class ASH_EXPORT OverviewSession : public display::DisplayObserver,
   // Perform cleanup that cannot be done in the destructor.
   void Shutdown();
 
+  bool IsAnyOverviewItemDragged() const;
+
   // Called when the last overview item from a grid is deleted.
   void OnGridEmpty();