No...definitely not.  Looks like this was broken back in August.  I'll fix this promptly.  It's a trivial change, would you like me to request merge to 65 if it is helpful?

I don't personally have a reason to, but I don't know who/what motivated its addition originally.

It was added to track user sequences of behavior based on how long people have been gone from Chrome.  This was to see if we could take different action based on how long you've not been using Chrome (i.e. open a new tab, show a sheet, etc..).

I'll just land the fix then.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0839c2de531c3b4d49c97699f853fc82d150c624

commit 0839c2de531c3b4d49c97699f853fc82d150c624
Author: Ted Choc <tedchoc@google.com>
Date: Wed Jan 24 22:15:52 2018

Fix main intent background duration startup metrics.

Accidentally broken by this refactoring:
https://chromium-review.googlesource.com/582338

Added tests to ensure the metric does not regress in the future.

BUG= 800625 

Change-Id: Iae1e29d11f62f177cea1200fa24befa64b77f559
Reviewed-on: https://chromium-review.googlesource.com/879433
Commit-Queue: Ted Choc <tedchoc@chromium.org>
Reviewed-by: Maria Khomenko <mariakhomenko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531708}
[modify] https://crrev.com/0839c2de531c3b4d49c97699f853fc82d150c624/chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java
[modify] https://crrev.com/0839c2de531c3b4d49c97699f853fc82d150c624/chrome/android/javatests/src/org/chromium/chrome/browser/metrics/MainIntentBehaviorMetricsIntegrationTest.java