From 5eb6b1e2b634889d46f5295ad53af77217340266 Mon Sep 17 00:00:00 2001 From: Noam Rosenthal Date: Tue, 12 Nov 2024 14:55:33 +0000 Subject: [PATCH] Update presentation-timestamps.md --- presentation-timestamps.md | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/presentation-timestamps.md b/presentation-timestamps.md index 20d24cc..330e562 100644 --- a/presentation-timestamps.md +++ b/presentation-timestamps.md @@ -53,7 +53,8 @@ See [Self-Review Questionnaire: Security and Privacy](https://w3ctag.github.io/s ### 01. What information might this feature expose to Web sites or other parties, and for what purposes is that exposure necessary? -It exposes timing information of a platform/OS operation, namely "VSync". +It exposes timing information of a platform/OS operation, namely "VSync". This is already exposed to some extend by the `requestAnimationFrame` callback timestamp. +It is necessary in order to reflect to web developers the impact on user experience performance in practice, as other metrics offer approximations that lose too much information. #### 02. Do features in your specification expose the minimum amount of information necessary to enable their intended uses? @@ -73,9 +74,9 @@ No. This feature only applies to the current document. #### 06. Do the features in your specification expose information about the underlying platform to origins? -To some extent, the timing of committing a frame is information about the underlying platform. +To some extent, the timing of committing a frame is information about the underlying platform, like the refresh rate. However, this information is already exposed in other ways (the `requestAnimationFrame` callback timestamp), -and in this specification it is over-coarsen to avoid exposing meaningful information in terms of security. +and in this specification it is coarsened on top of the usual coarsening, to avoid exposing meaningful information in terms of security/fingerprinting. #### 07. Does this specification allow an origin to send data to the underlying platform?