Changes in 20210816094534

Built from 36974366b0fbc17ac7e2ee7e6a39ce6cead207fa

..index..
Bug 1692609 A[Core:DOM: Core & HTML]resist-fingerprinting makes it hard to have smooth (60hz) animations
Bug 1724846 R[Core:Graphics: WebRender]Split DL spatial tree to separate payload
Bug 1725893 R[Core:Layout]Replace nsLayoutUtils::GetCrossDocParentFrame in nsIFrame::GetScreenRectInAppUnits with nsLayoutUtils::GetCrossDocParentFrameInProcess
Bug 1725593 R[Core:Spelling checker]Get rid of SendCheckAndSuggest sync IPC
###########
Changes to 4 bugs - 3 fixed.