Intent to Remove: Prefixed Resource Timing buffer-management API

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Kunihiko Sakamoto

Jan 5, 2017, 11:42:08 PM1/5/17
to blink-dev

Primary eng (and PM) emails

Link to “Intent to Deprecate” thread

No deprecate thread; a deprecation message was added as part of the Intent to ship unprefixed Resource Timing API.


Remove webkitClearResourceTimings(), webkitSetResourceTimingBufferSize(), and onwebkitresourcetimingbufferfull from the Performance interface, in favor of clearResourceTimings(), setResourceTimingBufferSize(), and onresourcetimingbufferfull.


This aligns ResourceTiming with the specification and Chrome’s general desire of not using prefixed features anymore.

Compatibility Risk


The webkit-prefixed APIs have been supported since Chrome 25 (Feb 2013). It was originally implemented in WebKit, but Safari has not enabled it. Firefox, IE 10+, and Edge have only unprefixed version of the API.

Deprecation message has been around for a long time, since Chrome 46 (Oct 2015).

Usage information from UseCounter

PrefixedPerformanceClearResourceTimings: 0.006%

PrefixedPerformanceSetResourceTimingBufferSize: 0.001%

PrefixedPerformanceResourceTimingBufferFull: 0.025%

The usage of onresourcetimingbufferfull is probably inflated since it's measuring any access to the attribute (not when events are actually fired).

OWP launch tracking bug

Entry on the feature dashboard

Ilya Grigorik

Jan 6, 2017, 12:20:44 AM1/6/17
to Kunihiko Sakamoto, blink-dev
\o/ .. yay! 

Dimitri Glazkov

Jan 6, 2017, 12:35:40 AM1/6/17
to Ilya Grigorik, Kunihiko Sakamoto, blink-dev

Chris Harrelson

Jan 6, 2017, 11:37:54 AM1/6/17
to Dimitri Glazkov, Ilya Grigorik, Kunihiko Sakamoto, blink-dev

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Jan 6, 2017, 12:37:57 PM1/6/17
to Chris Harrelson, Dimitri Glazkov, Ilya Grigorik, Kunihiko Sakamoto, blink-dev
I thought there was an "Alternatives for web developers" section in the intent template, or is it only in the intent to deprecate template?

I know the summary already states it, but it is better to spell it out in its own section (and on ChromeStatus) for easier look up for web developers.


Kunihiko Sakamoto

Jan 9, 2017, 10:36:17 PM1/9/17
to PhistucK, Chris Harrelson, Dimitri Glazkov, Ilya Grigorik, Kunihiko Sakamoto, blink-dev
Yeah the alternatives section was only in the intent-to-deprecate template.

For this case, alternatives are the unprefixed buffer-management API:
  • performance.clearResourceTimings()
  • performance.setResourceTimingBufferSize()
  • performance.onresourcetimingbufferfull

Rick Byers

Jan 10, 2017, 2:21:28 PM1/10/17
to Kunihiko Sakamoto, PhistucK, Chris Harrelson, Dimitri Glazkov, Ilya Grigorik, blink-dev
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