[ios] Adds contextual_search and omnibox resources

ios/chrome/browser/ui/omnibox/BUILD.gn

 # 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("omnibox") {
   sources = [
     "omnibox_util.cc",
     "omnibox_util.h",
     "web_omnibox_edit_controller.cc",
     "web_omnibox_edit_controller.h",
   ]
   deps = [
     "//base",
     "//components/omnibox/browser",
     "//components/security_state/core",
     "//ios/chrome/app/theme",
   ]
 }
+
+bundle_data("resources") {
+  sources = [
+    "resources/omnibox_background.png",
+    "resources/omnibox_background@2x.png",
+    "resources/omnibox_background@3x.png",
+    "resources/omnibox_transparent_background.png",
+    "resources/omnibox_transparent_background@2x.png",
+    "resources/omnibox_transparent_background@3x.png",
+  ]
+  outputs = [
+    "{{bundle_resources_dir}}/{{source_file_part}}",
+  ]
+}