Remove old cc-frame-viewer now that it is upstreamed into trace_viewer

tools/cc-frame-viewer/src/ui/list_and_associated_view.css

-/* Copyright (c) 2012 The Chromium Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file. */
-x-list-and-associated-view {
-    display: -webkit-flex;
-    -webkit-flex-direction: row;
-}
-
-x-list-and-associated-view > x-list-view {
-    min-width: 100px;
-}
-
-x-list-and-associated-view > :nth-child(2) {
-    -webkit-flex: 1;
-}