---
title: Firefox 51 для разработчиков
slug: Mozilla/Firefox/Releases/51
translation_of: Mozilla/Firefox/Releases/51
---
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Установить Firefox Developer EditionFirefox 51 был выпущен 24 января 2017 года.
В этой статье перечислены ключевые изменения, которые полезны не только для веб-разработчиков, но и для разработчиков Firefox и Gecko, а также для разработчиков приложений.
Изменения для веб-разработчиков
Инструменты разработчика
HTML
No change.
CSS
- Implemented
inset() value for {{cssxref("clip-path")}} behind the preference layout.css.clip-path-shapes.enabled, defaulting to false ({{bug(1246762)}}).
- [css-grid] Implement {{cssxref("fit-content()")}} value for <track-size> ({{bug(1281320)}}).
- [css-grid] Percentage gutters are wrong calculated on grid containers with indefinite sizes ({{bug(1279182)}}).
- [css-grid] Reject repeat() column tracks in <grid-template> when there's a grid template area string in the row part ({{bug(1282643)}}).
- Implemented {{cssxref(":indeterminate")}} for <input type="radio"> ({{bug(885359)}}).
- Implemented {{cssxref(":placeholder-shown")}} pseudo-class ({{bug(1069015)}}).
- Unprefixed {{cssxref("::placeholder")}} pseudo-element ({{bug(1069012)}}).
JavaScript
- The ES2015 {{jsxref("Symbol.toStringTag")}} property has been implemented ({{bug(1114580)}}).
Interfaces/APIs/DOM
DOM & HTML DOM
- Throttling in background tabs of timers created by {{domxref("WindowTimers.setInterval", "Window.setInterval()")}} and {{domxref("WindowTimers.setTimeout", "Window.setTimeout()")}} was changed in Firefox 50 to no longer occur if a Web Audio API {{domxref("AudioContext")}} is actively playing sound. However, this didn't resolve all scenarios in which timing-sensitive audio playback (such as music players generating individual notes using timers) could fail to work properly. For that reason, Firefox 51 no longer throttles background tabs which have an {{domxref("AudioContext")}}, even if it's not currently playing sound.
Canvas
No change.
WebGL
No change.
IndexedDB
No change.
Service Workers
No change.
WebRTC
No change.
New APIs
No change.
Others
No change.
MathML
No change.
SVG
- Added {{SVGAttr("tabindex")}} attribute ({{bug(778654)}}).
- Added {{SVGAttr("href")}} attribute obsoleting {{SVGAttr("xlink:href")}} ({{bug(1245751)}}).
Audio/Video
- Add FLAC support (FLAC codec) in both FLAC and Ogg containers ({{bug(1195723)}}).
- FLAC mimetype:
- FLAC in Ogg:
audio/ogg; codecs=flacvideo/ogg; codecs=flac
HTTP
No change.
Networking
No change.
Security
No change.
Changes for add-on and Mozilla developers
Interfaces
No change.
XUL
No change.
JavaScript code modules
No change.
XPCOM
No change.
Other
- The Mozilla-specific Social API has been substantially changed (largely to remove APIs no longer used), as follows:
- The {{domxref("MozSocial")}} interface and the {{domxref("navigator.mozSocial")}} property which supports it have been removed.
- The Social Bookmarks API has been removed.
- The Social chat functionality has been removed.
- The Social Status API has been removed.
- All of the social widgets, except for the Share panel, have been removed. This includes the social sidebar, flyover panels, and so forth.
- All supporting user interface features and functionality for the removed APIs have been removed as well.
- Social service provider manifest properties supporting the removed functionality are no longer supported.
See also
Older versions
{{Firefox_for_developers(50)}}