Add unit tests for the Background Scheduler.

chrome/android/java/src/org/chromium/chrome/browser/offlinepages/TaskExtrasPacker.java

Index: chrome/android/java/src/org/chromium/chrome/browser/offlinepages/TaskExtrasPacker.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/TaskExtrasPacker.java b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/TaskExtrasPacker.java
new file mode 100644
index 0000000000000000000000000000000000000000..88ed872eb6630060b452fbb7e7bce0124dab93cd
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/TaskExtrasPacker.java
@@ -0,0 +1,25 @@
+// 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.chrome.browser.offlinepages;
+
+import android.os.Bundle;
+
+/**
+ * Class to put our custom task information into the task bundle.
+ */
+public class TaskExtrasPacker {
+    /** Bundle key for the timestamp in milliseconds when the request started. */
+    public static final String DATE_TAG = "Date";

[dougarnett, 2016/06/03 21:51:53]

We may want to end up naming with more meaningful name like SCHEDULED_TIME_TAG
or REQUESTED_TIME_TAG  

[Pete Williamson, 2016/06/03 23:52:29]

Done.

+
+    /** Puts current time into the input bundle. */
+    public static void packTimeInBundle(Bundle bundle) {
+        bundle.putLong(DATE_TAG, System.currentTimeMillis());
+    }
+
+    /** Extracts the time we put into the bundle. */
+    public static long unpackTimeFromBundle(Bundle bundle) {
+        return bundle.getLong(DATE_TAG);
+    }
+}