Added UnguessableToken.java .

base/android/jni_unguessable_token.h

Index: base/android/jni_unguessable_token.h
diff --git a/base/android/jni_unguessable_token.h b/base/android/jni_unguessable_token.h
new file mode 100644
index 0000000000000000000000000000000000000000..c42845271b5be0757bbd3252aec54a306d8b5884
--- /dev/null
+++ b/base/android/jni_unguessable_token.h
@@ -0,0 +1,36 @@
+// Copyright 2016 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 BASE_ANDROID_JNI_UNGUESSABLE_TOKEN_H_

[nyquist, 2016/11/08 19:04:42]

We usually use jni_foo_thing.h naming for things that have to do with our
handling of JNI itself, such as JavaRef, strings, numbers, arrays, etc., not for
wrapper classes around code with real business logic.

How about naming this unguessable_token_android.h? (similarly to
memory_pressure_listener_android.* in the same directory)

[liberato (no reviews please), 2016/11/09 18:18:33]

thanks, Done.

+#define BASE_ANDROID_JNI_UNGUESSABLE_TOKEN_H_
+
+#include <jni.h>
+
+#include "base/android/scoped_java_ref.h"
+#include "base/base_export.h"
+#include "base/unguessable_token.h"
+
+namespace base {
+namespace android {
+
+// Create a java UnguessableToken with the same value as |token|.

[nyquist, 2016/11/08 19:04:42]

Nit: Java

[liberato (no reviews please), 2016/11/09 18:18:33]

Done.

+BASE_EXPORT ScopedJavaLocalRef<jobject> CreateJavaUnguessableToken(
+    JNIEnv* env,
+    const base::UnguessableToken& token);
+
+// Create a native UnguessableToken from |token|.

[nyquist, 2016/11/08 19:04:42]

Nit: Could you specify which Java type |token| must be?

[liberato (no reviews please), 2016/11/09 18:18:33]

Done.

+BASE_EXPORT base::UnguessableToken ConvertFromJavaUnguessableToken(
+    JNIEnv* env,
+    const JavaRef<jobject>& token);
+
+// Parcel |token| and unparcel it, and return the result.  While this method is
+// intended for facilitating unit tests, it results only in a clone of |token|.
+BASE_EXPORT ScopedJavaLocalRef<jobject>
+ParcelAndUnparcelUnguessableTokenForTesting(JNIEnv* env,
+                                            const JavaRef<jobject>& token);
+
+}  // namespace android
+}  // namespace base
+
+#endif  // BASE_ANDROID_JNI_UNGUESSABLE_TOKEN_H_