WebKit

Pointer Events

• Added PointerEvent in the Experimental Features menu
• Ensured PointerEvent is not visible when disabled

WebRTC

• Added RTCCodecStats support
• Changed to allow IP mismatch for local connections on localhost
• Cleaned up change handling for RealtimeMediaSource settings
• Fixed video track clone to preserve original property
• Implemented sender and receiver getStats
• Updated constraints supported by getDisplayMedia

Media

• Enabled H.264 Simulcast
• Enabled Modern Encrypted Media API by default in the Experimental Features menu
• Added WebM sanitization in EME
• Introduced the concept of CDMInstanceSession for EME
• Changed to use some tolerance when deciding whether a frame should be appended to the decode queue in MSE
• Fixed a comparison with an uninitialized greatestDecodeDuration in MSE
• Fixed an unwanted erased sample from the decode queue in MSE
• Fixed WebVTT cue alignment
• Updated the WebVTT parser according to new region syntax

CSS

• Fixed item alignment next to collapsed tracks with gutters in CSS Grid
• Restricted the total combined size of backdrop filters
• Fixed CSS reference filter with feDisplacementMap buffer corruption on Retina displays
• Fixed updating feMorphology filter in CSS when the element moves
• Fixed a garbled rendering of an image when feConvolveMatrix is applied to it on a Retina display
• Started implementing CSS Custom Properties and Values
• Implemented initialValue support for CSS Custom Properties and Values API
• Made overflow:overlay a synonym for overflow:auto
• Fixed
  in quirks mode to have margin-block-end:1em

JavaScript

• Implemented BigInt support for bitwise & operation
• Optimized Array#indexOf in the C++ runtime
• Optimized Array#lastIndexOf in the C++ runtime

Web Animations

• Fixed accelerated animations to get suspended
• Fixed endlessly calling DocumentTimeline::updateAnimations()
• Ensured renderers with accelerated animations have layers

Shadow DOM

• Added the support for users to select content across shadow boundaries
• Added the support for copying content across shadow boundaries

Web API

• Fixed custom elements in a reaction queue losing its JavaScript wrapper and becoming an HTMLUnknownElement
• Fixed elements enqueued in mutation observers losing its JavaScript wrappers
• Changed Image.proto to be a Function.prototype not an HTMLElement.prototype
• Fixed radio inputs and checkbox inputs to fire "click", "input", and "change" events in order when clicked
• Simplified authentication code
• Changed document.open() to not propagate URLs to non-fully active documents
• Changed document.open() to throw errors for cross-origin calls
• Changed to strip the fragment from the document URL during document.open() URL propagation
• Fixed no-op document.open() calls to ensure no side effects
• Dropped support for the cross-origin-window-policy header

Apple Pay

• Added support for granular errors in PaymentDetailsUpdate
• Removed the "in-store" button type

Web Inspector

• Fixed an issue that caused Web Inspector’s tabs to be hidden when docked to the side
• Fixed an issue that caused dock buttons to disappear when Web Inspector goes fullscreen
• The Debugger tab now has one unified section for all breakpoint types
• Fixed the light background on new watch expression popover in Dark Mode
• Fixed image resources without content getting shown when the Images folder is selected
• Removed the Legacy Style Editor
• Removed the Visual Style CSS details sidebar panel
• Reworked the Computed panel in the Styles sidebar panel to match the styles of the Rules panel
• Added an experimental setting for multi-property selection
• Changed to start editing property names and values on mouseup instead of mousedown in the Styles sidebar

Web Driver

• Fixed an issue wherein sending a Tab key press could sometimes shift focus out of web content and hang the WebDriver session
• Fixed an issue that caused safaridriver to immediately abort on launch
• Fixed an issue where the Perform Actions command failed if a keyboard input source specified a tick containing a "pause" value without a "key" value

Storage

• Fixed an WebSQL issue preventing the user from granting a quota increase if the JavaScript provides an expected usage value that is too low