[hryhoriiK97]

Summary:

Once a component's props are set with setNativeProps, ShadowNode::clone applies family.nativeProps_DEPRECATED again every time one of its shadow nodes is cloned with unchanged props: it parses them into new props with cloneProps. That includes the clones Yoga makes of every child of a node it lays out (YogaLayoutableShadowNode::adoptYogaChild), so each commit that touches a parent re-parses the native props of all its children that ever had setNativeProps, and nativeProps_DEPRECATED stays set for the life of the component.

On Fabric, JS-driven Animated (useNativeDriver: false) updates props with setNativeProps on every frame (shouldUseSetNativePropsInFabric, on by default). With several animated components under one parent, every frame re-parses the props of all of them, not just the one being updated. For a Text, new props also mark its Yoga node dirty (ParagraphShadowNode::shouldNewRevisionDirtyMeasurement), so all of them are measured again. In a list of 30 JS-animated texts, on Android that was ~16,000 measurePreparedLayout calls per second (~40 per frame), and on iOS props parsing was 27–28% of the JS thread.

With this change, ShadowNodeFamily counts changes to nativeProps_DEPRECATED (setNativeProps_DEPRECATED, and UIManager::cloneNode when a React render updates them), and each shadow node records the count its props include. A clone with unchanged props keeps the source node's count; ShadowNode::clone applies nativeProps_DEPRECATED only when the node it clones is behind, exactly as before in every other case. So native props are still applied after setNativeProps and after a React render replaces a node's props; they are only no longer parsed again into props that already include them.

Changelog:

[GENERAL] [CHANGED] - Fabric no longer parses the props set by setNativeProps again on every clone of a component's shadow nodes

Test Plan:

• New FabricUIManagerTest cases: after setNativeProps_DEPRECATED, a clone of a node whose props include them keeps the same props object, and a later setNativeProps_DEPRECATED is applied to the next clone; after a React render (cloneNode) replaces a node's props, the next clone applies the native props again. These C++ tests run internally; locally I compiled the test file against the real headers with a stub gtest (clang++ -fsyntax-only), as OSS CI doesn't run ReactCommon gtests.
• yarn fantom with the setNativeProps reconciliation tests (Mounting-itest.js, ReactNativeElement-itest.js) and the Animated suites that drive JS animations through setNativeProps (AnimatedComponents, AnimatedComposition, AnimatedValue, TimingAnimation): 6 suites, 285 tests pass.
• node scripts/clang-format.js --check reports no changes for the touched files.
• No C++ API snapshot changes: the new ShadowNodeFamily field is excluded by _DEPRECATED and the new ShadowNode field is private.
• On devices, a Playground screen of 30 Animated.Text rows with JS-driven loops (even rows animate color, odd rows fontSize), RNTester release builds:
  • Android, moto g57 power (Android 16), two APKs from the same local checkout (main at f7de203 with local benchmark screens and call counters), installed alternately, 20 s per run, three rounds. "Before" is a build with this check behind a runtime switch, turned off, so clone re-applies nativeProps_DEPRECATED every time as on main; "this PR" is this change as is:

	before	this PR	change
measurePreparedLayout JNI calls per second	16,038 / 16,151 / 15,986	2,079 / 2,073 / 2,068	−87%
Text draws per second (animation throughput)	548 / 551 / 548	762 / 754 / 761	+39%
JS thread, 20 s (saturated in both)	20.5 / 20.7 / 20.6 s	19.0 / 18.9 / 18.9 s	−8%, −33% per Text draw
Main thread, 20 s	3.52 / 3.44 / 3.50 s	3.24 / 3.10 / 3.20 s	−9%

A control screen without setNativeProps (200 single-style numbers changing every 100 ms) is unchanged: JS time per text layout 0.45 → 0.44 ms, main thread 2.30 → 2.33 s.

• iOS, iPhone 15 Pro (iOS 26.6.1), the same check behind a runtime switch in one build, Time Profiler for 12 s per run, two rounds each: props parsing (cloneProps and its callees) fell from 27–28% of the JS thread (1,608 / 2,708 ms) to 4.4–4.5% (158 / 208 ms). Total JS and main-thread times varied too much between runs on this phone to compare.

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