Affected Version: 2.15-rc2-2704-g36faf7c5c4

What steps will reproduce the problem?
1. Go to https://chromium-review.googlesource.com/c/chromium/tools/build/+/909350
2. Click "Reland"

What is the expected output?
Unknown. Never seen this work before. I figure it'll navigate me to another page or something.

What do you see instead?
The button turns grey and nothing happens.

Please provide any additional information below.
I went into the dev console, and it makes a request to https://chromium-review.googlesource.com/changes/909350/revisions/2/cherrypick, which gets a 409 response with the text "Cherry pick failed: identical tree"