Define a single macro for enabling backup function.

chrome/browser/sync/profile_sync_service_unittest.cc

 // Copyright (c) 2012 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.
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/run_loop.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 469 matching lines @@
   EXPECT_EQ(GoogleServiceAuthError::AuthErrorNone(),
             token_status.last_get_token_error);
   EXPECT_TRUE(token_status.next_token_request_time.is_null());
 
   // Simulate successful connection.
   service()->OnConnectionStatusChange(syncer::CONNECTION_OK);
   token_status = service()->GetSyncTokenStatus();
   EXPECT_EQ(syncer::CONNECTION_OK, token_status.connection_status);
 }
 
-#if defined(OS_WIN) || defined(OS_MACOSX) || (defined(OS_LINUX) && !defined(OS_CHROMEOS))
+#if defined(ENABLE_PRE_SYNC_BACKUP)
 void QuitLoop() {
   base::MessageLoop::current()->Quit();
 }
 
 TEST_F(ProfileSyncServiceTest, StartBackup) {
   CreateServiceWithoutSignIn();
   ExpectDataTypeManagerCreation(1);
   std::vector<bool> delete_dir_param;
   ExpectSyncBackendHostCreationCollectDeleteDir(1, &delete_dir_param);
   Initialize();
@@ skipping 95 matching lines @@
             ProfileSyncService::GetSyncServiceURL(command_line).spec());
 
   // See that we can override the URL with a flag.
   command_line.AppendSwitchASCII("--sync-url", "https://foo/bar");
   EXPECT_EQ("https://foo/bar",
             ProfileSyncService::GetSyncServiceURL(command_line).spec());
 }
 
 }  // namespace
 }  // namespace browser_sync