histogram-extension

Overview

This skill outlines how you (the agent) should automatically locate and extend the expiration dates of UMA histograms in Chromium that have expired or are nearing expiration.

Workflow

1. Discovery & Locate (Delegated)

AI-Led Discovery: Delegate to the generalist sub-agent to find histograms that are nearing expiration if none are provided. Run:
bash
```
python3 scripts/find_candidates.py --count 1
```
Bug Checking: Check references/bug_discovery.md and Buganizer to ensure the metric isn't already being extended in another ticket.
Locate: Look inside tools/metrics/histograms/metadata/*/histograms.xml to find the target metric.
Look for the <histogram name="TARGET_NAME" expires_after="YYYY-MM-DD"> definition (or enum=... expires_after="...").

2. Update the Expiration Date

Ask the user (or read from the brief) what the new expiration date should be. If none is specified, recommend extending by +6 months or +1 year (in YYYY-MM-DD format).
Carefully replace the expires_after="YYYY-MM-DD" string constraint inline, being sure not to modify other attributes.

3. Commit and CL creation

Create the Git commit with a descriptive, code-health aligned message using the metadata template below.
Skill Name: histogram-extension
Branch Name: histogram-extension-[histogram-name]
Commit Hashtag: Code Health
Cleanup Title: Extend expiration for [Histogram Name]
Cleanup Description: This metric is still actively needed for telemetry monitoring. Extending expiration to prevent data loss.
Parent Bug: 499059543
Bug ID: The resolved <Bug ID> from the Bug Checking step.
Upload the CL to Gerrit and add the appropriate metadata reviewers depending on the OWNERS file located in tools/metrics/histograms/metadata/{category}/OWNERS.