The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ce18f330c76f5c43f85dc15543ba9d7e3316c4e5

commit ce18f330c76f5c43f85dc15543ba9d7e3316c4e5
Author: kdsilva <kdsilva@google.com>
Date: Wed Jul 06 11:50:59 2016

Removing CustomLayout media notification logic

Removed code and the Feature flag related to the
CustomLayout media notification logic since it was replaced with
MediaStyle notification in M52.

BUG= 613564 

Review-Url: https://codereview.chromium.org/2119353003
Cr-Commit-Position: refs/heads/master@{#403885}

[delete] https://crrev.com/5009e3effbb04c74140d262fb71bc51cbf38913a/chrome/android/java/res/layout/playback_notification_bar.xml
[modify] https://crrev.com/ce18f330c76f5c43f85dc15543ba9d7e3316c4e5/chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java
[modify] https://crrev.com/ce18f330c76f5c43f85dc15543ba9d7e3316c4e5/chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaNotificationManager.java
[modify] https://crrev.com/ce18f330c76f5c43f85dc15543ba9d7e3316c4e5/chrome/android/java/src/org/chromium/chrome/browser/media/ui/MediaSessionTabHelper.java
[modify] https://crrev.com/ce18f330c76f5c43f85dc15543ba9d7e3316c4e5/chrome/android/javatests/src/org/chromium/chrome/browser/media/ui/NotificationTitleUpdatedTest.java
[modify] https://crrev.com/ce18f330c76f5c43f85dc15543ba9d7e3316c4e5/chrome/app/generated_resources.grd
[modify] https://crrev.com/ce18f330c76f5c43f85dc15543ba9d7e3316c4e5/chrome/browser/about_flags.cc
[modify] https://crrev.com/ce18f330c76f5c43f85dc15543ba9d7e3316c4e5/chrome/browser/android/chrome_feature_list.cc
[modify] https://crrev.com/ce18f330c76f5c43f85dc15543ba9d7e3316c4e5/chrome/browser/android/chrome_feature_list.h