The following histograms are present in Chromium source code but do not
appear in histograms.xml.

ExtensionInstallSigner.FetchSuccess defined at
chrome/browser/extensions/install_signer.cc line 415
https://cs.chromium.org/chromium/src/chrome/browser/extensions/install_signer.cc?l=415

ExtensionInstallSigner.GetResponseSuccess defined at
chrome/browser/extensions/install_signer.cc line 422
https://cs.chromium.org/chromium/src/chrome/browser/extensions/install_signer.cc?l=422

ExtensionInstallSigner.ParseFieldsSuccess defined at
chrome/browser/extensions/install_signer.cc line 463
https://cs.chromium.org/chromium/src/chrome/browser/extensions/install_signer.cc?l=463

ExtensionInstallSigner.ParseJsonSuccess defined at
chrome/browser/extensions/install_signer.cc line 443
https://cs.chromium.org/chromium/src/chrome/browser/extensions/install_signer.cc?l=443

File and line information may be out-of-date by the time you read this.

Please remove these histograms from the source code. If they were very
recently added, it may be worth adding them to histograms.xml instead, but
probably not.

This bug was automatically assigned based on git blame information. If you
are not the correct assignee for this bug, please delete the histograms
anyway.