Changes in 20201220093524

Built from 13f304ed6039df4f00c1f64d186a1f5a914d07b2

..index..
Bug 1680828 R[Core:DOM: Core & HTML]Blocking Autoplay and Cosmetic Animations Does not Block Autoplaying Marquee on Kickstarter
Bug 1683027 R[Core:DOM: UI Events & Focus Handling][GTK][Fcitx5] Redundant `keydown` events may be fired if active IME is Fcitx5 and there is no composition
Bug 1683461 R[Core:GFX: Color Management]Remove the final unsafety from chain.rs.
Bug 1683373 R[Core:Security: Process Sandboxing]Add whether User CET is available into the the Telemetry Environment on Windows
Bug 1683263 R[Firefox:Installer]Use typographic apostrophes consistently in Firefox strings
Bug 1398481 R[Toolkit:Add-ons Manager]WebExtensions - Embedded add-on options page does not zoom when Add-ons Manager (about:addons) page is zoomed
Bug 1679452 R[Toolkit:Themes]Replace :not(X):not(Y) with :not(X, Y)
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Changes to 7 bugs - 7 fixed.