Gemini Metrics & Telemetry Layer

Last updated: May 2026

This directory contains the metrics, histograms, and user actions tracking for the Gemini (BWG) feature integration on Chrome for iOS. It facilitates telemetry collection for onboarding consent, session engagement, AI latency, and hardware feature permissions.

Monitored Telemetry Areas

1. First Run Experience (Consent & Promos)

• FRE Promotion Action: Records user choices (Accept/Dismiss/Link Click) when presented with the Gemini FRE introductory promo (RecordFREPromoAction).
• FRE Consent Action: Tracks similar user actions on the main Gemini Consent sheet (RecordFREConsentAction), recording link clicks for South Korea and standard flows.
• FRE State Tracker: Records preference states related to whether a user has completed, bypassed, or dismissed the onboarding flow.

2. Prompt & Context Statistics

• Prompt Submission Method: Records methods used to send queries (e.g. direct text inputs, edit menu text selections, smart suggestion chips, or omnibox prompts).
• Attachment Stats: Logs image counts attached per query, as well as remix triggers and long-press inclusions.
• Page Context Status: Logs if page context (annotated inner text) is attached when submitting a query.

3. AI Service & Network Latency

• Response Latency: Logs prompt-to-response round-trip times, partitioned by whether page context was shared (Latency.WithContext vs Latency.WithoutContext) or if an image was generated (Latency.WithGeneratedImage).
• First Response Tracker: Logs latency and success when the first query response is successfully received in a new session.

4. Session Duration & Engagement

• Session Engagement: Tracks total queries per session and sessions that are abandoned vs successfully completed.
• Session Length: Records elapsed duration between floaty presentation and dismissal, segmented by first-run status.
• Transition Tracking: Logs visual transitions (e.g., collapsed to expanded, hidden to shown) and minimize/maximize durations.

5. Camera Permission Workflow

• OS Camera Permissions: Telemetry tracking initial authorization statuses (Authorized, Denied, NotDetermined) and the final consent result.
• Permissions Alert: Records button taps on the Custom Settings prompt if permissions are denied, and the camera picker results (completed with/without image or canceled).

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File Index

File	Description
gemini_metrics.h / .mm	Public API declaring UMA histogram keys, metric enums, and recording functions.
gemini_metrics_unittest.mm	Unit tests asserting correct histogram population, bucketing, and mock session durations.
BUILD.gn	GN build targets defining metrics dependencies.