cros: Only SEND_GESTURE_EVENTS_TO_OWNER if in drag

Do not SEND_GESTURE_EVENTS_TO_OWNER unless the icon is in a drag.

Example: We used to send this runtype for all gesture events. This does
not work as expected for two finger taps.

Bug: 906692
Change-Id: Ie1c5f16f2d0552df6147b9abf3b495c63b69ce93
Reviewed-on: https://chromium-review.googlesource.com/c/1346953Reviewed-by: Weidong Guo <weidongg@chromium.org>
Commit-Queue: Alex Newcomer <newcomer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610128}

ash/app_list/views/app_list_item_view.cc

@@ -472,7 +472,7 @@ void AppListItemView::OnContextMenuModelReceived(
                   views::MenuRunner::FIXED_ANCHOR |
                   views::MenuRunner::CONTEXT_MENU;
 
-  if (source_type == ui::MENU_SOURCE_TOUCH)
+  if (source_type == ui::MENU_SOURCE_TOUCH && touch_dragging_)
     run_types |= views::MenuRunner::SEND_GESTURE_EVENTS_TO_OWNER;
 
   gfx::Rect anchor_rect = apps_grid_view_->GetIdealBounds(this);