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

tools/cc-frame-viewer/src/lthi_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-lthi-view {
-    display: block;
-    -webkit-flex-direction: column;
-}
-
-x-lthi-view > x-lthi-view-options {
-    display: inline-span;
-    margins: 0 auto 0 auto;
-    border-bottom: 1px solid rgba(0,0,0,.25);
-}
-
-x-lthi-view > x-lthi-view-options > span:not(:nth-child(1)),
-x-lthi-view > x-lthi-view-options > label:not(:nth-child(1)) {
-    margin-left: 16px;
-}
-
-x-lthi-view > x-lthi-view-options > span {
-    margin-right: 8px;
-}
-
-
-x-lthi-view > x-quad-views {
-    display: -webkit-flex;
-    -webkit-flex-direction: row;
-}
-
-x-lthi-view > x-quad-views > *:not(:first-child) {
-    margin-left: 16px;
-}