The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e60cd0c367c85708ce720719443ae0e58c08b59d

commit e60cd0c367c85708ce720719443ae0e58c08b59d
Author: ianwen <ianwen@chromium.org>
Date: Wed Apr 20 20:05:36 2016

[Custom Tabs]Unbreak buttons on bottom bar

After thre refactoring related to remoteviews based bottom bar, the old
API stopped working. This CL fixes the breakage.

BUG= 604849 

Review URL: https://codereview.chromium.org/1895813004

Cr-Commit-Position: refs/heads/master@{#388559}

[modify] https://crrev.com/e60cd0c367c85708ce720719443ae0e58c08b59d/chrome/android/java/res/values/ids.xml
[modify] https://crrev.com/e60cd0c367c85708ce720719443ae0e58c08b59d/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabBottomBarDelegate.java
[modify] https://crrev.com/e60cd0c367c85708ce720719443ae0e58c08b59d/chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/CustomTabActivityTest.java

Your change meets the bar and is auto-approved for M51 (branch: 2704)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6e1eac4cfd970cf00c4ff28fcd9f7877584cdd48

commit 6e1eac4cfd970cf00c4ff28fcd9f7877584cdd48
Author: Ian Wen <ianwen@google.com>
Date: Thu Apr 21 21:41:03 2016

[Custom Tabs]Unbreak buttons on bottom bar

After thre refactoring related to remoteviews based bottom bar, the old
API stopped working. This CL fixes the breakage.

BUG= 604849 

Review URL: https://codereview.chromium.org/1895813004

Cr-Commit-Position: refs/heads/master@{#388559}
TBR=yusufo@chromium.org

Review URL: https://codereview.chromium.org/1908173002 .

Cr-Commit-Position: refs/branch-heads/2704@{#173}
Cr-Branched-From: 6e53600def8f60d8c632fadc70d7c1939ccea347-refs/heads/master@{#386251}

[modify] https://crrev.com/6e1eac4cfd970cf00c4ff28fcd9f7877584cdd48/chrome/android/java/res/values/ids.xml
[modify] https://crrev.com/6e1eac4cfd970cf00c4ff28fcd9f7877584cdd48/chrome/android/java/src/org/chromium/chrome/browser/customtabs/CustomTabBottomBarDelegate.java
[modify] https://crrev.com/6e1eac4cfd970cf00c4ff28fcd9f7877584cdd48/chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/CustomTabActivityTest.java

Fixed in M51.

I'm seeing this issue in the new Chrome Beta version 51.0.2704.28. 

I'm seeing this issue in the new Chrome Beta version 51.0.2704.28. Only on N. Works fine for me on M.

Updated N to NRD27C and I no longer see this. Thanks.