This update discusses the 1,522 WebKit and 2,131 Chromium changes that landed in the past two weeks, totaling up to 3,653 changes.

Chromium updated the libvpx library to include support for an early version of the VP9 decoder, the successor of the VP8 codec that’s currently used by WebM. Furthermore, though still behind a flag (also available in about:flags), WebM files containing audio streams using the Opus codec are now supported as well.

The Toolbar Icons in Web Inspector won’t be shown by default anymore. The gear icon immediately goes to the Settings dialog again. Newly added items to the Network Panel will now be applied to filtering and cookies can be sorted by their size again. The viewport-related warning messages have been cleaned up, a new warning has been added for scripts blocked by @sandbox and messages created by console.time and timeEnd() can now be filtered out.

Support has been added for the “widows”, “orphans” CSS properties, as well as for the “ruby-position” property. The text-orientation property now supports the “sideways-right” value and text decorations will now work correctly when text-combine is being used as well. Furthermore, out-of-range values will now be clamped to values the supported range. Applying SVG filters to elements through the url() syntax will now work even when the filter isn’t available yet, and CSS Exclusions’ shape-inside is now supported for multiple-segment polygons.

Elliot moved generated content in :before and :after CSS pseudo-elements to the DOM, which also means that supporting animations and transitions on them is close. The Shadow DOM’s ShadowRoot constructor is gone, XMLHttpRequests for blob data will now set their Content-Type header accordingly and status events will now be fired for <link rel=prerender> elements. The Web Audio API now supports an offline audio context and the ::cue pseudo-element for video elements now is supported as well.

Support for in-band text tracks is now available on the Mac port, and plumbing has been added to allow deferring displaying of text tracks to the embedder.

Following the final pieces of it’s implementation, Alexis enabled support for the new background-position offset syntax on several platforms before enabling it by default, and removing the feature flag altogether. Meanwhile Tab started on aligning WebKit’s gradient implementation with the specification, towards unprefixing.

As for more experimental features, work on implementing CSS Grid Layout continues with improved parsing and layouting capabilities. Rick started working on supporting -webkit-image-set() on cursors, too.

Other changes which occurred these weeks:

• All of Opera’s submitted <track> tests have been imported to WebKit’s Layout Test suite.
• Filip introduced a new profiler to the JavaScriptCore engine.
• Transferring large strings to workers through postMessage is now up to ten times faster for v8.
• The copy of the Acid3 test in WebKit’s sources has been updated to the latest version.
• WebKit’s old implementation of an Animation API has been removed from the code.
• A Web Inspector server for the EFL Port using WebKit2 has been added.
• A Chromium for Android performance bot was added to WebKit’s waterfall.
• The BlackBerry port enabled support for the image-resolution CSS property, and now uses libjpeg-turbo.
• The EFL port enabled support for WebGL by default.
• Chromium has enabled support for the Resource and User Timing APIs.
• The Apple Windows port enabled support for the <track> element.
• The EyesFree library was imported in Chromium for braille support, supposedly for Android.
• Support for the <dialog> element is now included in Chromium’s experimental WebKit feature set.
• A skeleton implementation of Google Now in Chrome landed.
• Local media streams (i.e. microphone input) can now be made audible through the <audio> element.

This will be the last update of 2012. Thank you for reading, have a Merry Christmas and a Happy New Year!!