[iOS/GN] Add code signing rules to ios_app_bundle target.

testing/test.gni

 # 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.
 
 # ==============================================================================
 # TEST SETUP
 # ==============================================================================
 
 template("_gen_isolate") {
   testonly = true
@@ skipping 289 matching lines @@
       # See above call.
       set_sources_assignment_filter([])
       forward_variables_from(invoker, "*", [ "testonly" ])
 
       # Provide sensible defaults in case invoker did not define any of those
       # required variables.
       if (!defined(info_plist) && !defined(info_plist_target)) {
         info_plist = "//testing/gtest_ios/unittest-Info.plist"
       }
       if (!defined(entitlements_path)) {
         entitlements_path = "//testing/gtest_ios"

[sdefresne, 2016/06/15 14:54:28]

"//testing/gtest_ios" is a directory and an invalid entitlements_path.

       }
-      if (!defined(code_signing_identity)) {
-        code_signing_identity = ""
-      }
 
       # TODO(crbug.com/603102): remove this once gyp support is dropped and all
       # application uses the target name as value for BUNDLE_ID_TEST_NAME.
       if (defined(invoker.app_name)) {
         app_name = invoker.app_name
       } else {
         app_name = target_name
       }
 
       if (!defined(extra_substitutions)) {
@@ skipping 40 matching lines @@
     if (defined(invoker.output_name) && target_name != invoker.output_name) {
       group("${invoker.output_name}_run") {
         testonly = true
         deps = [
           ":${invoker.target_name}",
         ]
       }
     }
   }
 }