Use "Organization Identifier" as prefix for gtest CFBundleIdentifier.

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
 # ==============================================================================
 
 # Define a test as an executable (or apk on Android) with the "testonly" flag
 # set.
@@ skipping 231 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"
       }
 
+      _bundle_id_suffix = target_name
+      if (ios_automatically_manage_certs) {
+        # Use the same bundle identifier for all unit tests when managing
+        # certificates automatically as the number of free certs is limited.
+        _bundle_id_suffix = "generic-unit-test"
+      }
       if (!defined(extra_substitutions)) {
         extra_substitutions = []
       }
-      extra_substitutions += [ "BUNDLE_ID_TEST_NAME=$target_name" ]
+      extra_substitutions += [ "GTEST_BUNDLE_ID_SUFFIX=$_bundle_id_suffix" ]
 
       if (!defined(deps)) {
         deps = []
       }
       deps += [
         # All shared libraries must have the sanitizer deps to properly link in
         # asan mode (this target will be empty in other cases).
         "//build/config/sanitizers:deps",
       ]
       if (!defined(bundle_deps)) {
@@ skipping 38 matching lines @@
 }
 
 # Test defaults.
 set_defaults("test") {
   if (is_android) {
     configs = default_shared_library_configs
   } else {
     configs = default_executable_configs
   }
 }