Changes in 20200607093436

Built from bbf2aac9fc58ff26d969c05d027507b4b03d145d

..index..
Bug 1642588 R[Core:DOM: Selection]contenteditable broken for triple-click-selection, if display:inline
Bug 1643634 R[Core:Graphics]let the WS_EX_LAYERED | WS_EX_TRANSPARENT flags on the compositor window ride the trains
Bug 1643137 R[Core:JavaScript Engine]Irregexp: Fix case-insensitive non-unicode backreferences
Bug 1642974 R[Core:JavaScript: GC]WeakRef should not expose DOM wrappers whose target has been cycle collected
Bug 1641139 R[Core:Layout: Ruby]Absolutely-positioned element in <ruby> is not shown
Bug 1619169 R[Core:Panning and Zooming]Planet mozilla content gets visibly clipped when dynamic toolbar is hidden on WebRender
Bug 1643532 R[Core:WebRTC]Intermittent TEST-UNEXPECTED-TIMEOUT | /webrtc/RTCRtpReceiver-getSynchronizationSources.https.html | [audio] getSynchronizationSources() eventually returns a non-empty list - Test timed out
Bug 1628599 R[DevTools:Documentation]Fix all links pointing to docs.firefox-dev.tools
Bug 1643270 R[DevTools:Netmonitor]Arrays/Objects in the Response panel are not expandable
Bug 1643639 R[Firefox:Address Bar]Hide some urlbar prefs that may cause trouble to the user
Bug 1637365 R[Firefox:Messaging System]Implement pre-importing topsites for multistage onboarding flow
Bug 1614773 R[Firefox:PDF Viewer]Port PDF viewer to fission/actors
Bug 1577457 R[Firefox:about:logins]Use :read-only/:read-write instead of [readOnly]/:not([readOnly]) in about:logins
Bug 1325771 R[Firefox Build System:General: Unsupported Platforms]Spidermonkey build support for Linux m68k broken
Bug 1640490 R[Toolkit:Reader Mode]Reader mode shows wrong content on some pages because it always re-fetches the article from the original URL
Bug 1642967 A[WebExtensions:General]Marking feeds as read in Feedbro RSS reader extension does not decrease unread number in sidebar
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Changes to 16 bugs - 15 fixed.
1 bugs are not included due to being restricted