Added UnguessableToken.java .

base/android/java/src/org/chromium/base/UnguessableToken.java

Index: base/android/java/src/org/chromium/base/UnguessableToken.java
diff --git a/base/android/java/src/org/chromium/base/UnguessableToken.java b/base/android/java/src/org/chromium/base/UnguessableToken.java
new file mode 100644
index 0000000000000000000000000000000000000000..4286f71191b4cf430edbe46c880efef94eef4235
--- /dev/null
+++ b/base/android/java/src/org/chromium/base/UnguessableToken.java
@@ -0,0 +1,70 @@
+// 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.
+
+package org.chromium.base;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+import org.chromium.base.annotations.CalledByNative;
+
+/**
+ * This class mirrors unguessable_token.h .  Since tokens are passed by value,
+ * we don't bother to maintain a native token.  This implements Parcelable so
+ * that it may be sent via binder.
+ *
+ * To get one of these from native, one must start with a
+ * base::UnguessableToken, then create a java object from it.  See
+ * jni_unguessable_token.h for information.
+ */
+public class UnguessableToken implements Parcelable {
+    private long mHigh;
+    private long mLow;
+
+    private UnguessableToken(long high, long low) {
+        mHigh = high;
+        mLow = low;
+    }
+
+    @CalledByNative
+    private static UnguessableToken create(long high, long low) {
+        return new UnguessableToken(high, low);
+    }
+
+    @CalledByNative
+    private long getHighForSerialization() {
+        return mHigh;
+    }
+
+    @CalledByNative
+    private long getLowForSerialization() {
+        return mLow;
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {

[liberato (no reviews please), 2016/11/02 22:18:24]

i need to add unit tests for these.  didn't see an easy way to write java-side
tests, so i'll probably need to add a private helper function.

+        dest.writeLong(mHigh);
+        dest.writeLong(mLow);
+    }
+
+    public static Parcelable.Creator<UnguessableToken> CREATOR =
+            new Parcelable.Creator<UnguessableToken>() {
+                @Override
+                public UnguessableToken createFromParcel(Parcel source) {
+                    final long high = source.readLong();
+                    final long low = source.readLong();
+                    return new UnguessableToken(high, low);
+                }
+
+                @Override
+                public UnguessableToken[] newArray(int size) {
+                    return new UnguessableToken[size];
+                }
+            };
+};