Bug 1703191. r=mccr8 Differential Revision: https://phabricator.services.mozilla.com/D111193

Bug 1682995 - Revert Enable AVIF support by default. r=aosmond,valentin,necko-reviewers,preferences-reviewers,Gijs Revert this change to turn AVIF off by default for now Differential Revision: https://phabricator.services.mozilla.com/D111892

Bug 1700963 - Stop relying on the "SessionStore:addSHistoryListener" message, r=nika We now create the listener after receiving a "browsing-context-did-set-embedder" and destroy it after receiving "browsing-context-discarded". Differential Revision: https://phabricator.services.mozilla.com/D110337

Bug 1700963 - Add a "browsing-context-did-set-embedder" observer notification, r=nika Differential Revision: https://phabricator.services.mozilla.com/D111709

Bug 1700963 - Clean up SessionStore's SHistoryListener, r=nika This does a few things: 1. Gets rid of the listener's `_sHistoryChanges` property, which is possible because _sHistoryChanges == false <-> _fromIdx == kNoIndex. 2. Simplifies the code that interacts with SHistoryListener in UpdateSessionStoreFromTablistener, and attempts to make that function a little more readable. 3. Ensures we're only doing the SessionHistory bit of UpdateSessionStoreFromTablistener for toplevel frames, and if SHIP is enabled. Differential Revision: https://phabricator.services.mozilla.com/D110336

Bug 1700215 - Make OverscrollAnimation coexist with momentum scrolling in the other axis. r=botond This change makes us match Chrome's overscroll behavior (i.e. restoring overscroll state on an axis while scrolling by pan momentum keeps going on the other axis). Basic mechanisms to do the behavior are; a) if there is an on-going overscroll animation on an axis and the overscroll direction is opposed to the momentum direction, stop the overscroll animation immediately and keep the momentum scroll (or overscroll and scroll if the current position is in overscroll gutter). b) if there is an on-going overscroll animation on an axis and the overscroll direction is same as the momentum direction, drop the momentum and keep the animation overscrolling. c) if there is an on-going overscroll animation on an axis and no overscroll animation on the other axis and if a pan momentum event overscrolls on the other axis, start a new overscroll animation on the axis. With this change there still remains a (relatively) less noticeable issue that pan momentum scrolling on an axis stops immediately after the other axis overscroll animation stopped. For example, given that there is a horizontal overscroll animation and vertical pan momentums keep going, subsequent vertical pan moments after the horizontal overscroll animation finished will be discarded since we do set the APZC state to NOTHING in AsyncPanZoomController::UpdateAnimation(). To fix this issue we need to handle OVERSCROLL_ANIMATION separately from the others, in the example case, once after the overscroll animation finished, the state should be MOMENTUMPAN, thus we can keep consuming momentum events as scroll. That said, the fix will not be easy, because there are also cumbersome cases where we don't want to keep consuming the events, one of the cases is b) in the basic mechanisms above, in the case we do want to discard incoming momentum events after the overscroll animation finished if the incoming momentum events are in the initial overscroll gutter, IF the incoming momentum events are in the another edge of the overscroll gutter, we have to re-initiate a new overscroll animation in the other side gutter. We will handle these cases in a followup bug (bug 1702949). Differential Revision: https://phabricator.services.mozilla.com/D110794

Bug 1700215 - Generate OverscrollAnimation only if it's overscrolled on the axis. r=botond This is a prerequisite change to keep momentum scrolls happening on the other axis where no overscroll animation is running. Differential Revision: https://phabricator.services.mozilla.com/D110793

Bug 1700215 - Introduce FingersOnTouchpad enum to represent whether fingers are still on touchpad. r=botond Boolean literals in call sites make it hard to tell what the value means. Differential Revision: https://phabricator.services.mozilla.com/D110792

Bug 1700215 - Factorout GetDisplacementsForPanGesture. r=botond Differential Revision: https://phabricator.services.mozilla.com/D110791

Bug 1703941 - Turn on prefs for new tab design work in Firefox 89. r=thecount Differential Revision: https://phabricator.services.mozilla.com/D111342

Bug 1695674 - Ensure we use RGB macro for FillRect r=emalysz We specify our colors like 0xrrggbb, but CreateSolidBrush expects a color created with the RGB macro, which actually arranges it as 0xbbggrr. This change has us use the RGB macro to give a color when creating the brush. Differential Revision: https://phabricator.services.mozilla.com/D107945

Bug 1695674 - Update Skeleton UI layout+colors to match Proton r=emalysz Differential Revision: https://phabricator.services.mozilla.com/D107944

Bug 1703967 - Added test case for getFontPreviewData(). r=jdescottes Differential Revision: https://phabricator.services.mozilla.com/D111560

Bug 1704026 - Adjust Add/Edit bookmark strings. r=Gijs Differential Revision: https://phabricator.services.mozilla.com/D112106

Bug 1704616 - enable proton modals by default r=jaws Differential Revision: https://phabricator.services.mozilla.com/D112038

Bug 1704616 - handle promise rejections from promiseDocumentFlushed in case the modal window goes away, r=mconley Differential Revision: https://phabricator.services.mozilla.com/D112102

Bug 1705216 - Use activateItem in browser/components/extensions/test/browser/browser_ext_tabs_executeScript_good.js. r=rpl Differential Revision: https://phabricator.services.mozilla.com/D112097

Bug 1515229 - Make MozStackWalk/MozWalkTheStack frame skipping more reliable. r=gerald,nika,bobowen,jld Differential Revision: https://phabricator.services.mozilla.com/D110899

Bug 1704879 - Use activateItem in browser/components/extensions/test/browser/head.js even if a button is used. r=robwu Depends on D111979 Differential Revision: https://phabricator.services.mozilla.com/D111980

Bug 1704879 - Allow specifying the command event's button field in XULPopupElement.activateItem. r=emilio Depends on D111956 Differential Revision: https://phabricator.services.mozilla.com/D111979