Add Cronet experimental option for host cache persistence

components/cronet/android/test/experimental_options_test.h

Index: components/cronet/android/test/experimental_options_test.h
diff --git a/components/cronet/android/test/experimental_options_test.h b/components/cronet/android/test/experimental_options_test.h
new file mode 100644
index 0000000000000000000000000000000000000000..95ee72444719ea9f869333f752aae87f949873b4
--- /dev/null
+++ b/components/cronet/android/test/experimental_options_test.h
@@ -0,0 +1,16 @@
+// Copyright 2017 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 COMPONENTS_CRONET_ANDROID_TEST_EXPERIMENTAL_OPTIONS_TEST_H_
+#define COMPONENTS_CRONET_ANDROID_TEST_EXPERIMENTAL_OPTIONS_TEST_H_
+
+#include <jni.h>
+
+namespace cronet {
+
+bool RegisterExperimentalOptionsTest(JNIEnv* env);
+
+}  // namespace cronet
+
+#endif  // COMPONENTS_CRONET_ANDROID_TEST_EXPERIMENTAL_OPTIONS_TEST_H_