Cherrypicking to 3017 fails with prohibited by Gerrit: ref update access denied.

The change is https://codereview.chromium.org/2846693003/.

I tried to cherrypick using git-drover, when that I failed I followed the manual instructions on the man page as shown below. Note that I have to skip the java formatting check as there is some git format conflict (after git cl format the presubmit still fails). I've reset my .gitcookies.

$ git checkout -b drover_3071 branch-heads/3071
$ git cherry-pick -x d9b19c661ed366be0c901cc45257160986bab530
  < fix a conflict, git cherry-pick --continue, verify diff >
$ git cl upload
$ git cl land --verbose
Using 50% similarity for rename/copy detection. Override with --similarity.
Running presubmit commit checks ...
Running /clank/sheriff/src/PRESUBMIT.py
Running /clank/sheriff/src/chrome/PRESUBMIT.py
Running /clank/sheriff/src/chrome/browser/PRESUBMIT.py

** Presubmit Messages **
--tbr was specified, skipping OWNERS check

** Presubmit Warnings **
The src directory requires source formatting. Please run git cl format .

Presubmit checks took 3.8s to calculate.

There were presubmit warnings. Are you sure you wish to continue? (y/N): y
Description:
Finch kill switch feature for background tab.

Adds the CCTBackgroundTab (ChromeFeatureList::CCT_BACKGROUND_TAB) feature
which is enabled by default.

Review-Url: https://codereview.chromium.org/2837873002
Cr-Commit-Position: refs/heads/master@{#467281}
(cherry picked from commit d9b19c661ed366be0c901cc45257160986bab530)

TBR=lizeb@chromium.org
BUG=708173

Review-Url: https://codereview.chromium.org/2846693003 .
 .../src/org/chromium/chrome/browser/ChromeFeatureList.java    |  1 +
 .../chrome/browser/customtabs/CustomTabsConnection.java       |  4 ++++
 .../chrome/browser/customtabs/CustomTabActivityTest.java      | 24 ++++++++++++++++++++++--
 chrome/browser/android/chrome_feature_list.cc                 |  4 ++++
 chrome/browser/android/chrome_feature_list.h                  |  1 +
 5 files changed, 32 insertions(+), 2 deletions(-)
[I2017-04-27 14:42:03,771 8112 139621852538688 git_cl.py] validator config enabled ['refs/heads/master', 'refs/branch-heads/*'] disabled [] refglobs for (this ref: refs/branch-heads/3071)
Attempt 1 of 3
Fetching origin/refs/branch-heads/3071...
From https://chromium.googlesource.com/chromium/src
 * [new ref]                   refs/branch-heads/3071 -> git-cl-cherry-pick
Cherry-picking commit on top of latest refs/branch-heads/3071
Counting objects: 25, done.
Delta compression using up to 32 threads.
Compressing objects: 100% (20/20), done.
Writing objects: 100% (25/25), 5.91 KiB | 0 bytes/s, done.
Total 25 (delta 14), reused 0 (delta 0)
remote: Resolving deltas: 100% (14/14)        
remote: Processing changes: refs: 1, done            
error: failed to push some refs to 'https://chromium.googlesource.com/chromium/src.git'
To https://chromium.googlesource.com/chromium/src.git
!	HEAD:refs/branch-heads/3071	[remote rejected] (prohibited by Gerrit: ref update access denied)
Done

Attempt 2 of 3
Fetching origin/refs/branch-heads/3071...
Cherry-picking commit on top of latest refs/branch-heads/3071
Counting objects: 25, done.
Delta compression using up to 32 threads.
Compressing objects: 100% (20/20), done.
Writing objects: 100% (25/25), 5.91 KiB | 0 bytes/s, done.
Total 25 (delta 14), reused 0 (delta 0)
remote: Resolving deltas: 100% (14/14)        
remote: Processing changes: refs: 1, done            
error: failed to push some refs to 'https://chromium.googlesource.com/chromium/src.git'
To https://chromium.googlesource.com/chromium/src.git
!	HEAD:refs/branch-heads/3071	[remote rejected] (prohibited by Gerrit: ref update access denied)
Done

Attempt 3 of 3
Fetching origin/refs/branch-heads/3071...
Cherry-picking commit on top of latest refs/branch-heads/3071
Counting objects: 25, done.
Delta compression using up to 32 threads.
Compressing objects: 100% (20/20), done.
Writing objects: 100% (25/25), 5.91 KiB | 0 bytes/s, done.
Total 25 (delta 14), reused 0 (delta 0)
remote: Resolving deltas: 100% (14/14)        
remote: Processing changes: refs: 1, done            
error: failed to push some refs to 'https://chromium.googlesource.com/chromium/src.git'
To https://chromium.googlesource.com/chromium/src.git
!	HEAD:refs/branch-heads/3071	[remote rejected] (prohibited by Gerrit: ref update access denied)
Done

Failed to push. If this persists, please file a bug.