GCAPI should append to the existing experiment_labels instead of clobbering them.

chrome/installer/gcapi/gcapi_test_registry_overrider.h

Index: chrome/installer/gcapi/gcapi_test_registry_overrider.h
diff --git a/chrome/installer/gcapi/gcapi_test_registry_overrider.h b/chrome/installer/gcapi/gcapi_test_registry_overrider.h
new file mode 100644
index 0000000000000000000000000000000000000000..3a7fa78f416eb27f23a97a54f50420e2e12ae991
--- /dev/null
+++ b/chrome/installer/gcapi/gcapi_test_registry_overrider.h
@@ -0,0 +1,23 @@
+// Copyright 2013 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.
+
+#ifndef CHROME_INSTALLER_GCAPI_GCAPI_TEST_REGISTRY_OVERRIDER_H_
+#define CHROME_INSTALLER_GCAPI_GCAPI_TEST_REGISTRY_OVERRIDER_H_
+
+#include "base/test/test_reg_util_win.h"
+
+// Overrides the registry throughout its lifetime; used by GCAPI tests
+// overriding the registry.
+class GCAPITestRegistryOverrider {
+ public:
+  GCAPITestRegistryOverrider();
+  ~GCAPITestRegistryOverrider();
+
+ private:
+  registry_util::RegistryOverrideManager override_manager_;
+
+  DISALLOW_COPY_AND_ASSIGN(GCAPITestRegistryOverrider);
+};
+
+#endif  // CHROME_INSTALLER_GCAPI_GCAPI_TEST_REGISTRY_OVERRIDER_H_