Refactor //ios:all target in preparation of upstreaming.

ios/testing/BUILD.gn

 # Copyright 2015 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.
 
 import("//ios/build/config.gni")
 import("//testing/test.gni")
 
+group("all_tests") {
+  testonly = true
+  deps = [
+    ":ocmock_support_unittest",
+  ]
+}
+
 source_set("ios_test_support") {
   configs += [ "//build/config/compiler:enable_arc" ]
   testonly = true
 
   deps = [
     "//base/test:test_support",
   ]
 
   sources = [
     "wait_util.h",
@@ skipping 61 matching lines @@
     "data/http_server_files/two_pages.pdf",
     "data/http_server_files/window_close.html",
     "data/http_server_files/window_open.html",
     "data/http_server_files/window_proxy.html",
   ]
   outputs = [
     "{{bundle_resources_dir}}/" +
         "{{source_root_relative_dir}}/{{source_file_part}}",
   ]
 }