[Clank] Add JNI interface for media persistent license storage

media/base/android/android_util.h

Index: media/base/android/android_util.h
diff --git a/media/base/android/android_util.h b/media/base/android/android_util.h
new file mode 100644
index 0000000000000000000000000000000000000000..2e7b9687c252a79f45884ce15f9506787961ac52
--- /dev/null
+++ b/media/base/android/android_util.h
@@ -0,0 +1,21 @@
+// 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.
+
+#include <memory>
+#include <string>
+
+#include "base/android/scoped_java_ref.h"
+
+namespace media {
+
+using JavaObjectPtr =
+    std::unique_ptr<base::android::ScopedJavaGlobalRef<jobject>>;
+
+// Converts jbyteArray (byte[] in Java) into std::string.
+std::string JavaBytesToString(JNIEnv* env, jbyteArray j_byte_array);
+
+// A helper method to create a JavaObjectPtr.
+JavaObjectPtr CreateJavaObjectPtr(jobject object);
+
+}  // namespace media