[tab_container] Remove tab_strip container

ios/showcase/tab_strip/BUILD.gn

Index: ios/showcase/tab_strip/BUILD.gn
diff --git a/ios/showcase/tab_strip/BUILD.gn b/ios/showcase/tab_strip/BUILD.gn
deleted file mode 100644
index 9be2c06d884b9e57002e0ba33d609c84391992ae..0000000000000000000000000000000000000000
--- a/ios/showcase/tab_strip/BUILD.gn
+++ /dev/null
@@ -1,17 +0,0 @@
-# Copyright 2016 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.
-
-source_set("tab_strip") {
-  sources = [
-    "sc_tab_strip_coordinator.h",
-    "sc_tab_strip_coordinator.mm",
-  ]
-  deps = [
-    "//ios/clean/chrome/browser/ui/actions",
-    "//ios/clean/chrome/browser/ui/tab_strip:tab_strip_ui",
-    "//ios/showcase/common",
-  ]
-  libs = [ "UIKit.framework" ]
-  configs += [ "//build/config/compiler:enable_arc" ]
-}