Mark gtest and gmock as testonly in GN.

sync/BUILD.gn

 # Copyright 2014 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("//build/config/features.gni")
 
 component("sync") {
   deps = [
     ":sync_core",
     "//sync/protocol",
@@ skipping 398 matching lines @@
       "//chromeos"
     ]
   }
 
   defines = [ "SYNC_IMPLEMENTATION" ]
   configs += [ "//build/config/compiler:wexit_time_destructors" ]
 }
 
 # GYP version: sync/sync_tests.gypi:test_support_sync_core
 static_library("test_support_sync_core") {
+  testonly = true
   sources = [
     "internal_api/public/base/model_type_test_util.cc",
     "internal_api/public/base/model_type_test_util.h",
     "js/js_test_util.cc",
     "js/js_test_util.h",
     "sessions/test_util.cc",
     "sessions/test_util.h",
     "test/callback_counter.h",
     "test/engine/fake_model_worker.cc",
     "test/engine/fake_model_worker.h",
@@ skipping 55 matching lines @@
 
   forward_dependent_configs_from = [
     "//testing/gmock",
     "//testing/gtest",
     "//sync"
   ]
 }
 
 # GYP version: sync/sync_tests.gypi:test_support_sync_internal_api
 static_library("test_support_sync_internal_api") {
+  testonly = true
   sources = [
     "internal_api/public/test/fake_sync_manager.h",
     "internal_api/public/test/null_sync_context_proxy.h",
     "internal_api/public/test/sync_manager_factory_for_profile_sync_test.h",
     "internal_api/public/test/test_entry_factory.h",
     "internal_api/public/test/test_internal_components_factory.h",
     "internal_api/public/test/test_user_share.h",
     "internal_api/test/fake_sync_manager.cc",
     "internal_api/test/null_sync_context_proxy.cc",
     "internal_api/test/sync_manager_factory_for_profile_sync_test.cc",
@@ skipping 16 matching lines @@
 
   forward_dependent_configs_from = [
     "//testing/gtest",
     "//sync",
     ":test_support_sync_core",
   ]
 }
 
 # GYP version: sync/sync_tests.gypi:test_support_sync_api
 static_library("test_support_sync_api") {
+  testonly = true
   sources = [
     "api/fake_syncable_service.cc",
     "api/fake_syncable_service.h",
     "api/fake_sync_change_processor.cc",
     "api/fake_sync_change_processor.h",
     "api/sync_change_processor_wrapper_for_test.cc",
     "api/sync_change_processor_wrapper_for_test.h",
     "api/sync_error_factory_mock.cc",
     "api/sync_error_factory_mock.h",
   ]
@@ skipping 122 matching lines @@
 
   if (is_ios) {
     sources -= [ "internal_api/http_bridge_unittest.cc" ]
   }
 
   defines = [ "SYNC_TEST" ]
 }
 
 # GYP version: sync/sync_tests.gypi:test_support_sync_fake_server
 static_library("test_support_sync_fake_server") {
+  testonly = true
   sources = [
     "test/fake_server/bookmark_entity.cc",
     "test/fake_server/bookmark_entity.h",
     "test/fake_server/bookmark_entity_builder.cc",
     "test/fake_server/bookmark_entity_builder.h",
     "test/fake_server/entity_builder.cc",
     "test/fake_server/entity_builder.h",
     "test/fake_server/entity_builder_factory.cc",
     "test/fake_server/entity_builder_factory.h",
     "test/fake_server/fake_server.cc",
@@ skipping 86 matching lines @@
       "//base",
       "//base/test:test_support",
       "//net:test_support",
       "//testing/gtest",
       ":test_support_sync_testserver",
     ]
   }
 }
 
 #TODO(GYP): Need to port sync_android.gypi and Android test targets.