Disable ShelfViewVisibleBoundsTest flaky tests

ash/shelf/shelf_view_unittest.cc

Index: ash/shelf/shelf_view_unittest.cc
diff --git a/ash/shelf/shelf_view_unittest.cc b/ash/shelf/shelf_view_unittest.cc
index 0051b29f7d54d26a4462ea8581e3e4009ac98037..6e93460575719592153e0ebe7c1964cd57545965 100644
--- a/ash/shelf/shelf_view_unittest.cc
+++ b/ash/shelf/shelf_view_unittest.cc
@@ -1957,7 +1957,14 @@ TEST_P(ShelfViewVisibleBoundsTest, ItemsAreInBounds) {
 }
 
 INSTANTIATE_TEST_CASE_P(LtrRtl, ShelfViewTextDirectionTest, testing::Bool());
-INSTANTIATE_TEST_CASE_P(VisibleBounds,
+
+// This test seems to be flaky with material design shelf (see
+// https://crbug.com/625671) and even in non-material mode (see
+// https://crbug.com/619344 which is fixed using a hack). Disabling for now.
+// TODO(mohsen): Hopefully, the fix for https://crbug.com/634128 that fixes
+// issues with shelf spacing, will fix this flake, too. Re-enable when that
+// issue is fixed.
+INSTANTIATE_TEST_CASE_P(DISABLED_VisibleBounds,
                         ShelfViewVisibleBoundsTest,
                         testing::Bool());