Firefox 72 for Developers 编辑

This article provides information about the changes in Firefox 72 that will affect developers. Firefox 72 was released on January 7, 2020.

Changes for web developers

You can now right/Ctrl click on objects in the Scopes panel, and choose Property set or Property get to set watchpoints (bug 1574192).

The Timings tab now shows queued, started, and downloaded times for each resource (bug 1580431).

No changes.

CSS Shadow Parts are now enabled. This includes the part attribute and ::part pseudo-element, which allow shadow hosts to selectively expose chosen elements from their shadow tree to the outside page for styling purposes (bug 1559074).
CSS Motion Path has been shipped (bug 1582554, also see the Intent to Ship). This includes:
The individual transform properties — scale, rotate, and translate — are now enabled by default (bug 1424900).

No changes

Notification.requestPermission() and PushManager.subscribe() can now only be called in response to a user gesture such as a click event (bug 1593644).

The MediaDevices.getDisplayMedia() method can now only be called in response to a user gesture such as a click event (bug 1580944).
The RTCRtpContributingSource dictionary can now include the rtpTimestamp property, which is a source-generated time at which the packet's media was generated or sampled (bug 1583867).

Removed the non-standard window.mozPaintCount property. (bug 1591968)
The BatteryManager interface is no longer exposed to web content (bug 1441976).
Navigator.vibrate() is no longer supported in cross-origin <iframe>s (bug 1591113).
WebRTC no longer supports the rid= and pt= parameters on the simulcast attribute. The new syntax for a line such as "a=simulcast: send rid=7 recv rid=8" is now "a=simulcast: send 7 recv 8". The new syntax has been supported since Firefox 68, so now it's time tor retire support for the old syntax (bug 1470568).

Opting-out of MIME sniffing using X-Content-Type-Options is now also applied to top-level documents if a Content-type is provided. This can cause HTML web pages to be downloaded instead of being rendered when they are served with a MIME type other than text/html. Make sure to set both headers correctly. (bug 1591932).
Dropped the support for HTTP Public Key Pinning (HPKP) because of the low adoption rate and interoperability risk. The Public-Key-Pins and Public-Key-Pins-Report-Only headers are now silently ignored bug 1412438.

No changes.

Removed Anon and AnonAttribute strategies from WebDriver:FindElement and WebDriver:FindElements commands (bug 1587627).
Webdriver:TakeScreenshot no longer fails if captured area exceeds upper maximum bound for the canvas width, height, or size (bug 1590064).

The browserSettings.ftpProtocolEnabled property has been implemented (bug 1592687).
The BrowserSetting.onChange event has been implemented (bug 1410412).
The captivePortal.canonicalURL property has been implemented (bug 1592932).
The callback functions for the browserAction.onClicked and pageAction.onClicked events now include a OnClickData property containing an object whose properties describe the mouse button pressed along with any keyboard modifiers (bug 1405031). This allows support for additional types of mouse click.