sheriff: disable All/AppsGridViewTest.MouseDragFlipPage

TBR=engedy@chromium.org

Bug: 1156634
Change-Id: I1158f342df683588d6c98d49080b798886e98034
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2578080Reviewed-by: Dominique Fauteux-Chapleau <domfc@chromium.org>
Commit-Queue: Dominique Fauteux-Chapleau <domfc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#834724}

ash/app_list/views/apps_grid_view_unittest.cc

@@ -1678,7 +1678,8 @@ TEST_F(AppsGridViewTest, ControlShiftArrowFolderLastItemOnPage) {
   EXPECT_TRUE(folder_item->FindChildItem(second_item_id));
 }
 
-TEST_P(AppsGridViewTest, MouseDragFlipPage) {
+// Flaky: crbug.com/1156634
+TEST_P(AppsGridViewTest, DISABLED_MouseDragFlipPage) {
   apps_grid_view_->set_page_flip_delay_in_ms_for_testing(10);
   GetPaginationModel()->SetTransitionDurations(
       base::TimeDelta::FromMilliseconds(10),