React sync for revisions ec6691a...55bc393

Summary:
This sync includes the following changes:
- **[55bc393f7](https://github.com/facebook/react/^Cmmit/55bc393f7 )**: [Flare] Ensure we check for bad polyfill when creating responders (#16243) //<Dominic Gannaway>//
- **[47656bf2a](https://github.com/facebook/react/^Cmmit/47656bf2a )**: [Flare] Remove longpress from press responder (#16242) //<Nicolas Gallagher>//
- **[9914a1919](https://github.com/facebook/react/^Cmmit/9914a1919 )**: [Fresh] Transfer refs when remounting (#16241) //<Dan Abramov>//
- **[75ab53b9e](https://github.com/facebook/react/^Cmmit/75ab53b9e )**: [scheduler] Yield many times per frame, no rAF (#16214) //<Andrew Clark>//
- **[0d7141dd4](https://github.com/facebook/react/^Cmmit/0d7141dd4 )**: [Flare] Fix SSR issue with serializing responders prop (#16227) //<Dominic Gannaway>//
- **[ed57bf8ed](https://github.com/facebook/react/^Cmmit/ed57bf8ed )**: [Bugfix] Check tag before calling hook effects (#16215) //<Andrew Clark>//
- **[858c84206](https://github.com/facebook/react/^Cmmit/858c84206 )**: Don't hyphenate custom CSS properties for ReactDOMServer (#16167) //<Belmin Bedak>//
- **[d412eec83](https://github.com/facebook/react/^Cmmit/d412eec83 )**: [act] flush work correctly without a mocked scheduler (#16223) //<Sunil Pai>//
- **[b43785e15](https://github.com/facebook/react/^Cmmit/b43785e15 )**: Update use-subscription README (#16216) //<Sophie Alpert>//
- **[c0830a0e6](https://github.com/facebook/react/^Cmmit/c0830a0e6 )**: [Scheduler] Test browser implementation details (#16198) //<Andrew Clark>//
- **[857deb2ed](https://github.com/facebook/react/^Cmmit/857deb2ed )**: Warn when Using DefaultProps on Function Components (#16210) //<lunaruan>//
- **[e0472709c](https://github.com/facebook/react/^Cmmit/e0472709c )**: [Flare] Adds Keyboard event responder (#16204) //<Dominic Gannaway>//
- **[5b08f7b43](https://github.com/facebook/react/^Cmmit/5b08f7b43 )**: [Flare] Adds useListener implementation to ReactDebugHooks (#16205) //<Dominic Gannaway>//
- **[ed72f4025](https://github.com/facebook/react/^Cmmit/ed72f4025 )**: [Flare] Remove references to EventComponent (#16206) //<Dominic Gannaway>//
- **[121bfb03b](https://github.com/facebook/react/^Cmmit/121bfb03b )**: update legacy context warning message (#16196) //<Sunil Pai>//
- **[9ae5e38f1](https://github.com/facebook/react/^Cmmit/9ae5e38f1 )**: Add guard to ensure Profiler onRender prop is function before calling (#16197) //<Brian Vaughn>//
- **[144dba1a1](https://github.com/facebook/react/^Cmmit/144dba1a1 )**: Fix suspenseCallback type warning, add a test (#16194) //<Benoit Girard>//
- **[7ad221126](https://github.com/facebook/react/^Cmmit/7ad221126 )**: [Flare] Ensure Flare components are no-ops for TestRenderer (#16192) //<Dominic Gannaway>//
- **[06cc99699](https://github.com/facebook/react/^Cmmit/06cc99699 )**: Edit Suspense Priority Warning Message (#16186) //<lunaruan>//
- **[42b75ab00](https://github.com/facebook/react/^Cmmit/42b75ab00 )**: Add suspenseCallback feature for runtime tracing of loading states (#16134) //<Benoit Girard>//
- **[c73e1f236](https://github.com/facebook/react/^Cmmit/c73e1f236 )**: flush work on exiting outermost act(), with nested act()s from different renderers (#16181) //<Sunil Pai>//
- **[509889119](https://github.com/facebook/react/^Cmmit/509889119 )**: [Flare] Redesign core event system (#16163) //<Dominic Gannaway>//
- **[19354db51](https://github.com/facebook/react/^Cmmit/19354db51 )**: [Scheduler] Add names to inline functions (#16180) //<Andrew Clark>//
- **[bff7abf6b](https://github.com/facebook/react/^Cmmit/bff7abf6b )**: [Scheduler][Bugfix] Multiple rAFs in same frame (#16184) //<Andrew Clark>//
- **[afb599168](https://github.com/facebook/react/^Cmmit/afb599168 )**: Enable profiler+tracing for test renderer (#16178) //<Brian Vaughn>//
- **[2237efcef](https://github.com/facebook/react/^Cmmit/2237efcef )**: [Fresh] Track unrecoverable errors (#16183) //<Dan Abramov>//
- **[bbd21066e](https://github.com/facebook/react/^Cmmit/bbd21066e )**: [Flare] Press: fix keyboard interactions (#16179) //<Nicolas Gallagher>//
- **[03944bfb0](https://github.com/facebook/react/^Cmmit/03944bfb0 )**: Update Suspense Priority Warning to Include Component that Triggered Update (#16030) //<lunaruan>//
- **[3f2cafe8b](https://github.com/facebook/react/^Cmmit/3f2cafe8b )**: [WIP][Scheduler] Use rIC to post first callback (#16166) //<Andrew Clark>//
- **[2bd88e38a](https://github.com/facebook/react/^Cmmit/2bd88e38a )**: [Scheduler] Bugfix: Cancelling a continuation (#16151) //<Andrew Clark>//
- **[783b8f4ae](https://github.com/facebook/react/^Cmmit/783b8f4ae )**: [Flare] Ensure mouse events can use target to validate press (#16172) //<Dominic Gannaway>//
- **[2c4d61e10](https://github.com/facebook/react/^Cmmit/2c4d61e10 )**: Adds experimental fundamental interface (#16049) //<Dominic Gannaway>//
- **[b4178af81](https://github.com/facebook/react/^Cmmit/b4178af81 )**: clean up nextEffect pointers (#16115) //<Paul Shen>//
- **[997154bcc](https://github.com/facebook/react/^Cmmit/997154bcc )**: [Flare] Add FocusWithin responder (#16152) //<Nicolas Gallagher>//
- **[65b80fdd9](https://github.com/facebook/react/^Cmmit/65b80fdd9 )**: [Flare] Add Input event responder surface (#16148) //<Dominic Gannaway>//
- **[ce883a19d](https://github.com/facebook/react/^Cmmit/ce883a19d )**: useSubscription hook (#15022) //<Brian Vaughn>//
- **[c45c2c3a2](https://github.com/facebook/react/^Cmmit/c45c2c3a2 )**: Move ReactFiberErrorDialog RN fork into RN itself (#16141) //<Moti Zilberman>//
- **[d9b4c55d5](https://github.com/facebook/react/^Cmmit/d9b4c55d5 )**: unify deprecated/unsafe lifecycle warnings, pass tests (#16103) //<Sunil Pai>//
- **[424099da6](https://github.com/facebook/react/^Cmmit/424099da6 )**: Inject getCurrentFiber() function to DevTools (#16133) //<Brian Vaughn>//
- **[9f395904c](https://github.com/facebook/react/^Cmmit/9f395904c )**: Inject ReactDebugCurrentFrame into DevTools so it can append component stacks to warnings in DEV mode (#16127) //<Brian Vaughn>//
- **[fcff9c57b](https://github.com/facebook/react/^Cmmit/fcff9c57b )**: Add tail="hidden" option to SuspenseList (#16024) //<Sebastian Markbåge>//
- **[8d413bf2c](https://github.com/facebook/react/^Cmmit/8d413bf2c )**: Remove React.error and React.warn (#16126) //<Brian Vaughn>//
- **[ca4d78f9b](https://github.com/facebook/react/^Cmmit/ca4d78f9b )**: [Flare] Press: fix middle-click handling (#16114) //<Nicolas Gallagher>//
- **[3f1dee09a](https://github.com/facebook/react/^Cmmit/3f1dee09a )**: expose act() sigil correctly for umd builds (#16110) //<Sunil Pai>//
- **[b7669044d](https://github.com/facebook/react/^Cmmit/b7669044d )**: Use Map instead of object as map in ReactNativeComponentTree (#16107) //<Sebastian Markbåge>//
- **[d2d9b1f70](https://github.com/facebook/react/^Cmmit/d2d9b1f70 )**: [Scheduler] Support inferring priority from stack (#16105) //<Andrew Clark>//
- **[48f659447](https://github.com/facebook/react/^Cmmit/48f659447 )**: Add warning when single item or nested arrays are used with SuspenseList (#16094) //<Sebastian Markbåge>//
- **[2073a7144](https://github.com/facebook/react/^Cmmit/2073a7144 )**: [Flare] Press includes button type (#16100) //<Nicolas Gallagher>//
- **[23b8a2534](https://github.com/facebook/react/^Cmmit/23b8a2534 )**: [Flare] Remove responder flags to simplify logic (#16084) //<Dominic Gannaway>//
- **[8533c0a16](https://github.com/facebook/react/^Cmmit/8533c0a16 )**: [Fabric] Add dispatchCommand to React Native renderers (#16085) //<Eli White>//
- **[2253bc81d](https://github.com/facebook/react/^Cmmit/2253bc81d )**: [Flare] Switch from currentTarget model to responderTarget model (#16082) //<Dominic Gannaway>//
- **[67e3f3fb6](https://github.com/facebook/react/^Cmmit/67e3f3fb6 )**: [Flare] Revise responder event types (#16081) //<Dominic Gannaway>//
- **[2a0f6390e](https://github.com/facebook/react/^Cmmit/2a0f6390e )**: Fix typos (#16076) //<Min ho Kim>//
- **[aa519c17c](https://github.com/facebook/react/^Cmmit/aa519c17c )**: [Flare] Add currentTarget and unify RN and DOM codepaths (#16066) //<Dominic Gannaway>//
- **[35d2b3bb5](https://github.com/facebook/react/^Cmmit/35d2b3bb5 )**: fix spelling error: resoltion ->  resolution (#16055) //<fnll>//
- **[bd72b0493](https://github.com/facebook/react/^Cmmit/bd72b0493 )**: [Flare] Clear pressStart timeout on pointercancel (#16067) //<Vincent Riemer>//
- **[c40075a72](https://github.com/facebook/react/^Cmmit/c40075a72 )**: [Flare] Remove capture phase Flare events (#16054) //<Dominic Gannaway>//
- **[786186c69](https://github.com/facebook/react/^Cmmit/786186c69 )**: [Flare] createInitialState -> getInitialState (#16051) //<Dominic Gannaway>//
- **[c64f40d71](https://github.com/facebook/react/^Cmmit/c64f40d71 )**: [Flare] Remove dead event target code (#16063) //<Dominic Gannaway>//
- **[e6bfa327d](https://github.com/facebook/react/^Cmmit/e6bfa327d )**: [Flare] Cleanup ReactFiberEvents-test (#16047) //<Dominic Gannaway>//
- **[b365ee281](https://github.com/facebook/react/^Cmmit/b365ee281 )**: [Fire] Remove unused React fire fork (#16046) //<Dominic Gannaway>//
- **[b8f91e664](https://github.com/facebook/react/^Cmmit/b8f91e664 )**: [fail] reset IsThisRendererActing correctly (#16042) //<Sunil Pai>//
- **[bd846459d](https://github.com/facebook/react/^Cmmit/bd846459d )**: [fail] Only warn on unacted effects for strict / non sync modes (#16041) //<Sunil Pai>//
- **[6b946ad9d](https://github.com/facebook/react/^Cmmit/6b946ad9d )**: [Flare] Add more functionality to Scroll event resonder (#16036) //<Dominic Gannaway>//
- **[a457e02ae](https://github.com/facebook/react/^Cmmit/a457e02ae )**: allow nested `act()`s from different renderers (#16039) //<Sunil Pai>//
- **[a865e4a64](https://github.com/facebook/react/^Cmmit/a865e4a64 )**: Clone a custom hook node before use (#16019) //<Anton Korzunov>//
- **[6cf2234a5](https://github.com/facebook/react/^Cmmit/6cf2234a5 )**: [Flare] Do not block mouse presses on scroll (#16033) //<Dominic Gannaway>//
- **[5cb8f6f34](https://github.com/facebook/react/^Cmmit/5cb8f6f34 )**: Add tail="collapsed" option to SuspenseList (#16007) //<Sebastian Markbåge>//
- **[46bd11ac3](https://github.com/facebook/react/^Cmmit/46bd11ac3 )**: Flush sync bug (#16027) //<lunaruan>//
- **[933c664ad](https://github.com/facebook/react/^Cmmit/933c664ad )**: SuspenseList Optimizations (#16005) //<Sebastian Markbåge>//
- **[fbbbea16e](https://github.com/facebook/react/^Cmmit/fbbbea16e )**: fix word async -> concurrent (#15844) //<Heaven>//
- **[eb2ace128](https://github.com/facebook/react/^Cmmit/eb2ace128 )**: [Flare] Bring Flare support to React Native Fabric (#15887) //<Dominic Gannaway>//
- **[9b0bd4355](https://github.com/facebook/react/^Cmmit/9b0bd4355 )**: [Flare] Re-label Flare flag (#16014) //<Dominic Gannaway>//
- **[8b88ac259](https://github.com/facebook/react/^Cmmit/8b88ac259 )**: [Flare] Remove event targets including TouchHitTarget (#16011) //<Dominic Gannaway>//
- **[f11540926](https://github.com/facebook/react/^Cmmit/f11540926 )**: Handle changes at module boundaries (#16002) //<Dan Abramov>//
- **[915dfe697](https://github.com/facebook/react/^Cmmit/915dfe697 )**: Slightly improve performance of hydration. (#15998) //<Benedikt Meurer>//
- **[824e9bec7](https://github.com/facebook/react/^Cmmit/824e9bec7 )**: [Flare] Fix issues with touch + pointer interactions (#15997) //<Dominic Gannaway>//
- **[dd93357aa](https://github.com/facebook/react/^Cmmit/dd93357aa )**: [Flare] Move click handling back into target phase (#15993) //<Dominic Gannaway>//
- **[4d307de45](https://github.com/facebook/react/^Cmmit/4d307de45 )**: Prefix mock Scheduler APIs with _unstable (#15999) //<Andrew Clark>//
- **[9b55bcfc6](https://github.com/facebook/react/^Cmmit/9b55bcfc6 )**: [Flare] Add Hooks to event modules (#15953) //<Brandon Dail>//
- **[20da1dae4](https://github.com/facebook/react/^Cmmit/20da1dae4 )**: Fix error logging in getDerivedStateFromProps (#15797) //<Ricky>//
- **[6088a201e](https://github.com/facebook/react/^Cmmit/6088a201e )**: [Flare] Fix Press scroll cancellation handling (#15983) //<Dominic Gannaway>//
- **[fd601fb21](https://github.com/facebook/react/^Cmmit/fd601fb21 )**: [Flare] Move all event responders to dom directory (#15981) //<Dominic Gannaway>//
- **[827cbc4d0](https://github.com/facebook/react/^Cmmit/827cbc4d0 )**: Rename StatelessComponent to FunctionComponent in react-is/README.md (#15963) //<Veniamin Krol>//
- **[d48db594e](https://github.com/facebook/react/^Cmmit/d48db594e )**: eslint-plugin-react-hooks@1.6.1 //<Dan Abramov>//
- **[7439b48cf](https://github.com/facebook/react/^Cmmit/7439b48cf )**: Add explicit support for ESLint 6.0.0 (#15974) //<Thomas Broyer>//
- **[fce15f14d](https://github.com/facebook/react/^Cmmit/fce15f14d )**: don't fire missing act() warnings for react-art (#15975) //<Sunil Pai>//
- **[20f354696](https://github.com/facebook/react/^Cmmit/20f354696 )**: [Flare] Ensure Press event hook does not execute side-effects (#15976) //<Dominic Gannaway>//
- **[d420d2ccb](https://github.com/facebook/react/^Cmmit/d420d2ccb )**: [Fresh] Retry failed roots on refresh (#15966) //<Dan Abramov>//
- **[04b77c630](https://github.com/facebook/react/^Cmmit/04b77c630 )**: followup to #15763, fix failing test in ReactDOMTracing-test (#15972) //<Sunil Pai>//
- **[e1c5e8720](https://github.com/facebook/react/^Cmmit/e1c5e8720 )**: warn if passive effects get queued outside of an act() call. (#15763) //<Sunil Pai>//
- **[39b97e8eb](https://github.com/facebook/react/^Cmmit/39b97e8eb )**: Report refreshed families to the caller (#15957) //<Dan Abramov>//
- **[d271df5c9](https://github.com/facebook/react/^Cmmit/d271df5c9 )**: Use function expression for custom Hook signature argument (#15956) //<Dan Abramov>//
- **[4189f712c](https://github.com/facebook/react/^Cmmit/4189f712c )**: [Scheduler] Increase max frame length to 300 //<Andrew Clark>//
- **[595c9414b](https://github.com/facebook/react/^Cmmit/595c9414b )**: [Scheduler] Fix navigator.isInputPending call //<Andrew Clark>//
- **[e7fcfe104](https://github.com/facebook/react/^Cmmit/e7fcfe104 )**: [scheduler] Put isPendingInput behind a flag (#15962) //<Andrew Clark>//
- **[6568a7993](https://github.com/facebook/react/^Cmmit/6568a7993 )**: [Scheduler] requestPaint (#15960) //<Andrew Clark>//
- **[8d4ddd33a](https://github.com/facebook/react/^Cmmit/8d4ddd33a )**: [Scheduler] Yield less if there's no pending input (#15959) //<Andrew Clark>//
- **[d77d12510](https://github.com/facebook/react/^Cmmit/d77d12510 )**: Expire rendering the tail of SuspenseList after a timeout (#15946) //<Sebastian Markbåge>//
- **[dc298fdf9](https://github.com/facebook/react/^Cmmit/dc298fdf9 )**: [Flare] Refinements to useEvent hook (#15955) //<Dominic Gannaway>//
- **[696609d49](https://github.com/facebook/react/^Cmmit/696609d49 )**: [Fiber] Clear down dependencies during detachFiber (#15947) //<Dominic Gannaway>//
- **[a5ed2f98f](https://github.com/facebook/react/^Cmmit/a5ed2f98f )**: [Flare] Guard against stateNode being null (#15952) //<Dominic Gannaway>//
- **[34ce57ae7](https://github.com/facebook/react/^Cmmit/34ce57ae7 )**: [Flare] Refine flow type annotations (#15950) //<Dominic Gannaway>//
- **[4f92fbce5](https://github.com/facebook/react/^Cmmit/4f92fbce5 )**: [Flare] Move createEvent back to React object (#15943) //<Dominic Gannaway>//
- **[175111de7](https://github.com/facebook/react/^Cmmit/175111de7 )**: Lazily initialize dependencies object (#15944) //<Andrew Clark>//
- **[720db4cbe](https://github.com/facebook/react/^Cmmit/720db4cbe )**: [Flare] Add useEvent hook implementation (#15927) //<Dominic Gannaway>//
- **[6ff4c9de1](https://github.com/facebook/react/^Cmmit/6ff4c9de1 )**: [Flare] Press: fix stale deactivation region state (#15931) //<Nicolas Gallagher>//
- **[7a4c3e3b7](https://github.com/facebook/react/^Cmmit/7a4c3e3b7 )**: Make global names more obscure (#15941) //<Dan Abramov>//
- **[270dc2e4d](https://github.com/facebook/react/^Cmmit/270dc2e4d )**: Add forwards and backwards options to SuspenseList (#15918) //<Sebastian Markbåge>//
- **[5368f7316](https://github.com/facebook/react/^Cmmit/5368f7316 )**: [Flare] Fix keyboard keyup regression (#15938) //<Dominic Gannaway>//
- **[3d0af2aea](https://github.com/facebook/react/^Cmmit/3d0af2aea )**: Don't consider require-like calls to be likely HOCs (#15940) //<Dan Abramov>//
- **[d4f384d25](https://github.com/facebook/react/^Cmmit/d4f384d25 )**: [Fresh] Throw in prod and change annotation (#15939) //<Dan Abramov>//
- **[ff91bfa58](https://github.com/facebook/react/^Cmmit/ff91bfa58 )**: [act] reset scope depth on synchronous errors (#15937) //<Sunil Pai>//
- **[e61c9e0a2](https://github.com/facebook/react/^Cmmit/e61c9e0a2 )**: [Flare] Fix Press retention state regression (#15936) //<Dominic Gannaway>//
- **[76864f7ff](https://github.com/facebook/react/^Cmmit/76864f7ff )**: Add SuspenseList Component (#15902) //<Sebastian Markbåge>//
- **[e9d0a3ff2](https://github.com/facebook/react/^Cmmit/e9d0a3ff2 )**: [Fresh] Track mounted roots via DevTools Hook (#15928) //<Dan Abramov>//
- **[35ef78de3](https://github.com/facebook/react/^Cmmit/35ef78de3 )**: [Scheduler] Integrated timers (#15911) //<Andrew Clark>//
- **[3af91eb8c](https://github.com/facebook/react/^Cmmit/3af91eb8c )**: [Scheduler] Use continuation pattern for posting host callback (#15910) //<Andrew Clark>//
- **[b62ae1642](https://github.com/facebook/react/^Cmmit/b62ae1642 )**: [Flare] Rename createEventComponent -> createEvent (#15929) //<Dominic Gannaway>//
- **[f4e1ac8ca](https://github.com/facebook/react/^Cmmit/f4e1ac8ca )**: [Flare] Press events include defaultPrevented (#15916) //<Nicolas Gallagher>//
- **[4a7a39b59](https://github.com/facebook/react/^Cmmit/4a7a39b59 )**: [Flare] Add RN build step for ReactTypes (#15926) //<Dominic Gannaway>//
- **[0bd755114](https://github.com/facebook/react/^Cmmit/0bd755114 )**: Remove mention of Prepack (#15922) //<Christoph Nakazawa>//
- **[689beef6f](https://github.com/facebook/react/^Cmmit/689beef6f )**: [Flare] Move unstable_createEventComponent to ReactDOM (#15890) //<Dominic Gannaway>//
- **[98454371a](https://github.com/facebook/react/^Cmmit/98454371a )**: Construct Error at invariant call site for clearer stack traces (#15877) //<Moti Zilberman>//
- **[f97b95166](https://github.com/facebook/react/^Cmmit/f97b95166 )**: [Flare] add disableContextMenu to Press (#15909) //<Nicolas Gallagher>//
- **[cd98e63b4](https://github.com/facebook/react/^Cmmit/cd98e63b4 )**: [Fresh] Fall back to Map/Set if Weak equivalents are not available (#15907) //<Dan Abramov>//
- **[a3c5b1fb8](https://github.com/facebook/react/^Cmmit/a3c5b1fb8 )**: [Fresh] Rename findHostNodesForHotUpdate to findHostInstancesForHotUpdate (#15904) //<Dan Abramov>//
- **[7985bf7d5](https://github.com/facebook/react/^Cmmit/7985bf7d5 )**: Remove outdated test renderer comments (#15898) //<Sebastian Markbåge>//
- **[f0156766d](https://github.com/facebook/react/^Cmmit/f0156766d )**: [Fresh] react-fresh => react-refresh (#15888) //<Dan Abramov>//
- **[801feed95](https://github.com/facebook/react/^Cmmit/801feed95 )**: Interaction tracing works across hidden and SSR hydration boundaries (#15872) //<Brian Vaughn>//
- **[661562fc5](https://github.com/facebook/react/^Cmmit/661562fc5 )**: Fix outdated test comments (#15892) //<Andrew Clark>//
- **[788da69b7](https://github.com/facebook/react/^Cmmit/788da69b7 )**: [Suspense] Fix bad loading state not being delayed (#15891) //<Andrew Clark>//
- **[353e0ee47](https://github.com/facebook/react/^Cmmit/353e0ee47 )**: [Flare] remove stopLocalPropagation option + modify responder ownership (#15889) //<Dominic Gannaway>//
- **[a146c1f9e](https://github.com/facebook/react/^Cmmit/a146c1f9e )**: [Flare] Refactor of Press to fix various issues (#15878) //<Dominic Gannaway>//
- **[de7a09c1e](https://github.com/facebook/react/^Cmmit/de7a09c1e )**: [Fresh] Make transform resilient to plugin order (#15883) //<Dan Abramov>//
- **[2fe8fd290](https://github.com/facebook/react/^Cmmit/2fe8fd290 )**: [Suspense] Use style.setProperty to set display (#15882) //<Andrew Clark>//
- **[e91dd70ba](https://github.com/facebook/react/^Cmmit/e91dd70ba )**: Remove disableYielding feature flag (#15654) //<Andrew Clark>//
- **[4d949d764](https://github.com/facebook/react/^Cmmit/4d949d764 )**: [React Native] Replace touch discrepancy errors to warnings (#15866) //<Timothy Yung>//
- **[45acbdc0b](https://github.com/facebook/react/^Cmmit/45acbdc0b )**: [Flare] Unsure root events are removed on contextmenu (#15862) //<Dominic Gannaway>//
- **[198ed661c](https://github.com/facebook/react/^Cmmit/198ed661c )**: [Suspense] Use !important to hide Suspended nodes (#15861) //<Andrew Clark>//
- **[191920605](https://github.com/facebook/react/^Cmmit/191920605 )**: [Fresh] Implement missing features (#15860) //<Dan Abramov>//
- **[c403ae4d3](https://github.com/facebook/react/^Cmmit/c403ae4d3 )**: [Flare] Move Press root event removal till click phase (#15854) //<Dominic Gannaway>//
- **[f4cd7a38d](https://github.com/facebook/react/^Cmmit/f4cd7a38d )**:  [Flare] Listen to document.body + add stopPropagation to Press (#15853) //<Dominic Gannaway>//
- **[425473f43](https://github.com/facebook/react/^Cmmit/425473f43 )**: [Flare] Improve runtime performance of hit target intersection (#15836) //<Dominic Gannaway>//
- **[def56c979](https://github.com/facebook/react/^Cmmit/def56c979 )**: [Fresh] Capture Hook signatures lazily on first render (#15832) //<Dan Abramov>//
- **[8cfcfe0fc](https://github.com/facebook/react/^Cmmit/8cfcfe0fc )**: [Flare] Fix ES6 issues with IE11 (#15834) //<Dominic Gannaway>//
- **[d0e041aee](https://github.com/facebook/react/^Cmmit/d0e041aee )**: [Fresh] Support classes by force-remounting them on edit (#15801) //<Dan Abramov>//
- **[73c27d8b4](https://github.com/facebook/react/^Cmmit/73c27d8b4 )**: [Flare] Add basic Scroll event responder module (#15827) //<Dominic Gannaway>//
- **[c72dceffb](https://github.com/facebook/react/^Cmmit/c72dceffb )**: [Flare] Small Swipe/Drag fixes (#15825) //<Dominic Gannaway>//
- **[6aaa43708](https://github.com/facebook/react/^Cmmit/6aaa43708 )**: Rename ReactFeatureFlags to remove the `.fb` suffix. (#15826) //<Christoph Nakazawa>//
- **[843a59ab6](https://github.com/facebook/react/^Cmmit/843a59ab6 )**: [React Native] Remove eventTypes from ReactNativeBridgeEventPlugin (#15802) //<Ricky>//
- **[7b28ad119](https://github.com/facebook/react/^Cmmit/7b28ad119 )**: [Flare] EventPriority enum (#15823) //<Andrew Clark>//
- **[d707a7579](https://github.com/facebook/react/^Cmmit/d707a7579 )**: nit: a quick copy edit for an act() message/comment (#15805) //<Sunil Pai>//
- **[cfb79ee5b](https://github.com/facebook/react/^Cmmit/cfb79ee5b )**: [Flare] Fix isTouchEvent (#15824) //<Dominic Gannaway>//
- **[6b5deeed5](https://github.com/facebook/react/^Cmmit/6b5deeed5 )**: [Events] Add support for events that are both user-blocking and continuous (#15811) //<Andrew Clark>//
- **[8d4fb132e](https://github.com/facebook/react/^Cmmit/8d4fb132e )**: [Flare] Fix nativeEvent.x/y for older browsers (#15820) //<Dominic Gannaway>//
- **[2534c0c92](https://github.com/facebook/react/^Cmmit/2534c0c92 )**: [Flare] Add event position properties to Hover responder (#15819) //<Dominic Gannaway>//
- **[dd43cb5fb](https://github.com/facebook/react/^Cmmit/dd43cb5fb )**: [Flare] Fix isPressWithinResponderRegion logic (#15808) //<Nicolas Gallagher>//
- **[4f6cab547](https://github.com/facebook/react/^Cmmit/4f6cab547 )**: [Flare] Ignore keyboard interactions on text input children (#15810) //<Nicolas Gallagher>//
- **[fa1e8df11](https://github.com/facebook/react/^Cmmit/fa1e8df11 )**: chore: use jest-serializer-raw for react-fresh snapshots (#15806) //<Simen Bekkhus>//
- **[07da821bf](https://github.com/facebook/react/^Cmmit/07da821bf )**: [react-native] Rewrite Haste imports in RN shims and add .fb.js extension (#15786) //<James Ide>//
- **[a383c4678](https://github.com/facebook/react/^Cmmit/a383c4678 )**: [ESLint] don't warn for Flow type variables (#15804) //<Jordan Rome>//
- **[5763f1d4c](https://github.com/facebook/react/^Cmmit/5763f1d4c )**: [Events] Nested discrete events across systems //<Andrew Clark>//
- **[7aa35ceae](https://github.com/facebook/react/^Cmmit/7aa35ceae )**: Fix casing of shouldflushDiscreteUpdates //<Andrew Clark>//
- **[91635dd48](https://github.com/facebook/react/^Cmmit/91635dd48 )**: Switch to "discrete" and "continuous" terminology //<Andrew Clark>//
- **[73c380fca](https://github.com/facebook/react/^Cmmit/73c380fca )**: WorkPhase -> ExecutionContext //<Andrew Clark>//
- **[88b396382](https://github.com/facebook/react/^Cmmit/88b396382 )**: [Flare] Remove deprecated keypress event (#15795) //<Nicolas Gallagher>//
- **[63fe08eef](https://github.com/facebook/react/^Cmmit/63fe08eef )**: React Events: allow Tab+Alt on Mac in Focus responder (#15679) //<Mateusz Burzyński>//
- **[113497cc0](https://github.com/facebook/react/^Cmmit/113497cc0 )**: [Suspense] Change Suspending and Restarting Heuristics (#15769) //<Sebastian Markbåge>//
- **[3b2302253](https://github.com/facebook/react/^Cmmit/3b2302253 )**: Fix sizebot (#15771) //<Andrew Clark>//
- **[0f7cc2ba8](https://github.com/facebook/react/^Cmmit/0f7cc2ba8 )**: React Events: check window before using navigator (#15768) //<Nicolas Gallagher>//
- **[2670bc340](https://github.com/facebook/react/^Cmmit/2670bc340 )**: React Events: support legacy browser Spacebar key value (#15766) //<Nicolas Gallagher>//
- **[9aad17d60](https://github.com/facebook/react/^Cmmit/9aad17d60 )**: using the wrong renderer's act() should warn (#15756) //<Sunil Pai>//
- **[1cc3bba00](https://github.com/facebook/react/^Cmmit/1cc3bba00 )**: Parallelizes the build script across multiple processes (#15716) //<Andrew Clark>//
- **[112168f31](https://github.com/facebook/react/^Cmmit/112168f31 )**: Lint rule for unminified errors (#15757) //<Andrew Clark>//
- **[142cf56cb](https://github.com/facebook/react/^Cmmit/142cf56cb )**: [Flare] Adds onContextMenu and fixes some contextmenu related issues (#15761) //<Dominic Gannaway>//
- **[556cc6fe1](https://github.com/facebook/react/^Cmmit/556cc6fe1 )**: [Fresh] Generate signatures for Hooks (#15733) //<Dan Abramov>//
- **[b74fa9868](https://github.com/facebook/react/^Cmmit/b74fa9868 )**: Clean up (#15755) //<Sebastian Markbåge>//
- **[d915a4c1f](https://github.com/facebook/react/^Cmmit/d915a4c1f )**: [Suspense] Add Batched Mode variant to fuzz tester (#15734) //<Andrew Clark>//
- **[401065fe5](https://github.com/facebook/react/^Cmmit/401065fe5 )**: Adds test for #15732. (#15747) //<Caleb Meredith>//
- **[287ef30bb](https://github.com/facebook/react/^Cmmit/287ef30bb )**: [Flare] Deeply prevent default on anchor elements (#15750) //<Dominic Gannaway>//
- **[a97b5c07b](https://github.com/facebook/react/^Cmmit/a97b5c07b )**: [Flare] More fixes for getAbsoluteBoundingClientRect (#15746) //<Dominic Gannaway>//
- **[393924879](https://github.com/facebook/react/^Cmmit/393924879 )**: [Fresh] Babel plugin now handles HOCs + add integration tests (#15724) //<Dan Abramov>//
- **[8af1f8792](https://github.com/facebook/react/^Cmmit/8af1f8792 )**: Rename ReactFiberScheduler -> ReactFiberWorkLoop and extract throwException from Unwind (#15725) //<Sebastian Markbåge>//
- **[399cd0d16](https://github.com/facebook/react/^Cmmit/399cd0d16 )**: Set up cron job to run fuzz tester (#15718) //<Andrew Clark>//
- **[025b07b61](https://github.com/facebook/react/^Cmmit/025b07b61 )**: [Flare] Ensure getAbsoluteBoundingClientRect aligns with offsetParent (#15720) //<Dominic Gannaway>//
- **[61f62246c](https://github.com/facebook/react/^Cmmit/61f62246c )**: [react-native] Use path-based imports instead of Haste for the RN renderer (#15604) //<James Ide>//
- **[b962adfc2](https://github.com/facebook/react/^Cmmit/b962adfc2 )**: [Flare] event component displayName is now mandatory (#15717) //<Dominic Gannaway>//
- **[5c2124fc7](https://github.com/facebook/react/^Cmmit/5c2124fc7 )**: [Fresh] Initial Babel plugin implementation (#15711) //<Dan Abramov>//
- **[b9ebc37c5](https://github.com/facebook/react/^Cmmit/b9ebc37c5 )**: Fix Flow (#15710) //<Dominic Gannaway>//
- **[a25a793fe](https://github.com/facebook/react/^Cmmit/a25a793fe )**: [Flare] update getEventCurrentTarget to use fiber tree (#15708) //<Dominic Gannaway>//
- **[b5dff62fa](https://github.com/facebook/react/^Cmmit/b5dff62fa )**: [Flare] Account for fixed elements in getAbsoluteBoundingClientRect (#15707) //<Dominic Gannaway>//
- **[f50f9ba5d](https://github.com/facebook/react/^Cmmit/f50f9ba5d )**: Fix ReactFiberNewContext spelling (#15692) //<Maksim Markelov>//
- **[e180f656f](https://github.com/facebook/react/^Cmmit/e180f656f )**: Flare: change flushDiscreteUpdates invariant to warning (#15702) //<Dominic Gannaway>//
- **[7829d8cf9](https://github.com/facebook/react/^Cmmit/7829d8cf9 )**: Fix missing return pointer assignment (#15700) //<Andrew Clark>//
- **[d7afe23f1](https://github.com/facebook/react/^Cmmit/d7afe23f1 )**: Rename "loading" to "busy" in SuspenseConfig API (#15699) //<Sebastian Markbåge>//
- **[ef4ac42f8](https://github.com/facebook/react/^Cmmit/ef4ac42f8 )**: [Flare] Update interactiveUpdates flushing heuristics (#15687) //<Dominic Gannaway>//
- **[6d4f85b61](https://github.com/facebook/react/^Cmmit/6d4f85b61 )**: [Fresh] Set up infra for runtime and Babel plugin (#15698) //<Dan Abramov>//
- **[121acae09](https://github.com/facebook/react/^Cmmit/121acae09 )**: Flare: simplify dispatchEvent discrete argument (#15694) //<Dominic Gannaway>//
- **[a398cbd5a](https://github.com/facebook/react/^Cmmit/a398cbd5a )**: Flare: update invalid accessor warnings + add no-ops (#15693) //<Dominic Gannaway>//
- **[9c9ea9485](https://github.com/facebook/react/^Cmmit/9c9ea9485 )**: flush only on exiting outermost act() (#15682) //<Sunil Pai>//
- **[50b50c26f](https://github.com/facebook/react/^Cmmit/50b50c26f )**: Inform DevTools of commit priority level (#15664) //<Brian Vaughn>//
- **[0bd9b5d00](https://github.com/facebook/react/^Cmmit/0bd9b5d00 )**: [Fresh] Support re-rendering lazy() without losing state (#15686) //<Dan Abramov>//
- **[ec38def44](https://github.com/facebook/react/^Cmmit/ec38def44 )**: [Fresh] Don't traverse remounted trees (#15685) //<Dan Abramov>//
- **[5731e522d](https://github.com/facebook/react/^Cmmit/5731e522d )**: [Fresh] Support lazy() and add Suspense tests (#15681) //<Dan Abramov>//
- **[31487dd82](https://github.com/facebook/react/^Cmmit/31487dd82 )**: [Fresh] Set up initial scaffolding (#15619) //<Dan Abramov>//
- **[9c6de716d](https://github.com/facebook/react/^Cmmit/9c6de716d )**: Add withSuspenseConfig API (#15593) //<Sebastian Markbåge>//
- **[1160b3769](https://github.com/facebook/react/^Cmmit/1160b3769 )**: Event API: Add responder allowMultipleHostChildren flag (#15646) //<Dominic Gannaway>//
- **[95e06ac3d](https://github.com/facebook/react/^Cmmit/95e06ac3d )**: Event API: isTargetWithinEventResponderScope on unmounted event components (#15672) //<Dominic Gannaway>//
- **[d278a3ff8](https://github.com/facebook/react/^Cmmit/d278a3ff8 )**: `act()` - s / flushPassiveEffects / Scheduler.unstable_flushWithoutYielding (#15591) //<Sunil Pai>//
- **[aad5a264d](https://github.com/facebook/react/^Cmmit/aad5a264d )**: Event API: ensure calculateResponderRegion accounts for page offset (#15671) //<Dominic Gannaway>//
- **[bb89b4eac](https://github.com/facebook/react/^Cmmit/bb89b4eac )**: Bail out of updates in offscreen trees (#15666) //<Dan Abramov>//
- **[4bf88ddec](https://github.com/facebook/react/^Cmmit/4bf88ddec )**: Fix <embed> not triggering onLoad (#15614) //<Andrew Cherniavskii>//
- **[f961050a3](https://github.com/facebook/react/^Cmmit/f961050a3 )**: Always flushPassiveEffects before rendering //<Andrew Clark>//
- **[b899819e7](https://github.com/facebook/react/^Cmmit/b899819e7 )**: Use dynamic flag in test renderer in www (#15662) //<Andrew Clark>//
- **[d34b457ce](https://github.com/facebook/react/^Cmmit/d34b457ce )**: Feature flag to revert #15650 (#15659) //<Andrew Clark>//
- **[668fbd651](https://github.com/facebook/react/^Cmmit/668fbd651 )**: Fix serial passive effects (#15650) //<Andrew Clark>//
- **[b0657fde6](https://github.com/facebook/react/^Cmmit/b0657fde6 )**: Event API: ensure getFocusableElementsInScope handles suspended trees (#15651) //<Dominic Gannaway>//
- **[8af90c897](https://github.com/facebook/react/^Cmmit/8af90c897 )**: Add test for nested avoided boundaries (#15636) //<Sebastian Markbåge>//
- **[af19e2eb2](https://github.com/facebook/react/^Cmmit/af19e2eb2 )**: Event API: adds pointerType to Focus events (#15645) //<Dominic Gannaway>//
- **[cc24d0ea5](https://github.com/facebook/react/^Cmmit/cc24d0ea5 )**: Invariant that throws when committing wrong tree (#15517) //<Andrew Clark>//
- **[83fc258f2](https://github.com/facebook/react/^Cmmit/83fc258f2 )**: Remove <ConcurrentMode /> (#15532) //<Andrew Clark>//
- **[283ce5320](https://github.com/facebook/react/^Cmmit/283ce5320 )**: Add ReactDOM.unstable_createSyncRoot (#15504) //<Andrew Clark>//
- **[862f499fa](https://github.com/facebook/react/^Cmmit/862f499fa )**: Add Batched Mode (#15502) //<Andrew Clark>//
- **[fec74f99d](https://github.com/facebook/react/^Cmmit/fec74f99d )**: Event API: ensure preventDefault works for nested targets (#15633) //<Dominic Gannaway>//
- **[edfedf3ae](https://github.com/facebook/react/^Cmmit/edfedf3ae )**: Fork ReactSharedInternals for UMD builds (#15617) //<Andrew Clark>//
- **[39ef609e7](https://github.com/facebook/react/^Cmmit/39ef609e7 )**: Update test to fix CI //<Andrew Clark>//
- **[5b6eb55e1](https://github.com/facebook/react/^Cmmit/5b6eb55e1 )**: Remove scheduler from React package dependencies (#15616) //<Andrew Clark>//
- **[0803d2247](https://github.com/facebook/react/^Cmmit/0803d2247 )**: Don't consider "Never" expiration as part of most recent event time (#15606) //<Sebastian Markbåge>//
- **[90f54d77f](https://github.com/facebook/react/^Cmmit/90f54d77f )**: Event API: add follow up event unwind test (#15612) //<Dominic Gannaway>//
- **[91a044e31](https://github.com/facebook/react/^Cmmit/91a044e31 )**: Event API: add key modifiers to Press events (#15611) //<Dominic Gannaway>//
- **[3d8b836e2](https://github.com/facebook/react/^Cmmit/3d8b836e2 )**: Event API: ensure we pop context for event system fibers (#15599) //<Dominic Gannaway>//
- **[e33e32db0](https://github.com/facebook/react/^Cmmit/e33e32db0 )**: Event API: normalize event timeStamp property to be in event system (#15598) //<Dominic Gannaway>//
- **[3669b9010](https://github.com/facebook/react/^Cmmit/3669b9010 )**: Event API: add more warnings for responder based events (#15597) //<Dominic Gannaway>//
- **[05d08500b](https://github.com/facebook/react/^Cmmit/05d08500b )**: Experimental Event API: Press event properties (#15586) //<Dominic Gannaway>//
- **[51e66cf9f](https://github.com/facebook/react/^Cmmit/51e66cf9f )**: Experimental Event API: reduce code size of event modules (#15590) //<Dominic Gannaway>//
- **[8abf243b8](https://github.com/facebook/react/^Cmmit/8abf243b8 )**: Ensure touch events are properly handled for pageX and pageY (#15587) //<Dominic Gannaway>//
- **[c7398f339](https://github.com/facebook/react/^Cmmit/c7398f339 )**: Add Suspense Boundary Context (and unstable_avoidThisFallback) (#15578) //<Sebastian Markbåge>//
- **[f9e60c8a1](https://github.com/facebook/react/^Cmmit/f9e60c8a1 )**: Warn when suspending at wrong priority (#15492) //<Andrew Clark>//
- **[89d8d1435](https://github.com/facebook/react/^Cmmit/89d8d1435 )**: Add React.unstable_createEventComponent (#15580) //<Nicolas Gallagher>//
- **[6da04b5d8](https://github.com/facebook/react/^Cmmit/6da04b5d8 )**: Fix interaction tracing for batched update mounts (#15567) //<Brian Vaughn>//
- **[d38cfd452](https://github.com/facebook/react/^Cmmit/d38cfd452 )**: Ensure TouchHitTarget element is server side rendered with hit slop (#15385) //<Dominic Gannaway>//
- **[2e5d1a8b9](https://github.com/facebook/react/^Cmmit/2e5d1a8b9 )**: React Events: fix cancel events for Press (#15563) //<Nicolas Gallagher>//
- **[307e0a7d7](https://github.com/facebook/react/^Cmmit/307e0a7d7 )**: React Events: cancel onLongPress for large enough moves (#15562) //<Nicolas Gallagher>//
- **[339366c46](https://github.com/facebook/react/^Cmmit/339366c46 )**: Event API: Support press reentry for pointer events (#15560) //<Dominic Gannaway>//

Changelog:
[General][Changed] - React sync for revisions ec6691a...55bc393

Reviewed By: yungsters

Differential Revision: D16555458

fbshipit-source-id: 2d71da52992fbb05b682247cfee20385d70a681b

Libraries/Renderer/REVISION

@@ -1 +1 @@
-87d375afd0d9394646a4bcddcebb7b15ffaa7e9e
+55bc393f726ddf3def83ca5a43cfc38a45d2e421