Introduce fuseboxFrameRecordingEnabled flag, gate existing code

Summary:
Replaces the previous `globalThis.enableTimelineFrames` setup with backend gating.

Enables us to:
- Iterate more safely by gating Android/iOS/C++ code
- Have a per-app rollout at Meta

Changelog: [Internal]

Differential Revision: D95405444

Author: huntie

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/devsupport/InspectorFlags.kt

@@ -20,4 +20,6 @@ internal object InspectorFlags {
   @DoNotStrip @JvmStatic external fun getFuseboxEnabled(): Boolean
 
   @DoNotStrip @JvmStatic external fun getIsProfilingBuild(): Boolean
+
+  @DoNotStrip @JvmStatic external fun getFrameRecordingEnabled(): Boolean
 }

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlags.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<66d3b8ed600077a287d6d7d8f6230b7b>>
+ * @generated SignedSource<<81d3efdeedd39107b06405f0f13ae5ce>>
  */
 
 /**
@@ -402,6 +402,12 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun fuseboxEnabledRelease(): Boolean = accessor.fuseboxEnabledRelease()
 
+  /**
+   * Enable frame timings and screenshots support in the React Native DevTools CDP backend. This flag is global and should not be changed across React Host lifetimes.
+   */
+  @JvmStatic
+  public fun fuseboxFrameRecordingEnabled(): Boolean = accessor.fuseboxFrameRecordingEnabled()
+
   /**
    * Enable network inspection support in the React Native DevTools CDP backend. Requires `enableBridgelessArchitecture`. This flag is global and should not be changed across React Host lifetimes.
    */

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxAccessor.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<98c5f6184864381e579a9df82741928b>>
+ * @generated SignedSource<<4801fec88223bbf304c494b538c91495>>
  */
 
 /**
@@ -82,6 +82,7 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
   private var fixYogaFlexBasisFitContentInMainAxisCache: Boolean? = null
   private var fuseboxAssertSingleHostStateCache: Boolean? = null
   private var fuseboxEnabledReleaseCache: Boolean? = null
+  private var fuseboxFrameRecordingEnabledCache: Boolean? = null
   private var fuseboxNetworkInspectionEnabledCache: Boolean? = null
   private var hideOffscreenVirtualViewsOnIOSCache: Boolean? = null
   private var overrideBySynchronousMountPropsAtMountingAndroidCache: Boolean? = null
@@ -667,6 +668,15 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun fuseboxFrameRecordingEnabled(): Boolean {
+    var cached = fuseboxFrameRecordingEnabledCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.fuseboxFrameRecordingEnabled()
+      fuseboxFrameRecordingEnabledCache = cached
+    }
+    return cached
+  }
+
   override fun fuseboxNetworkInspectionEnabled(): Boolean {
     var cached = fuseboxNetworkInspectionEnabledCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxInterop.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<2bf2a1dec031145181f6bc28c50cf32a>>
+ * @generated SignedSource<<9ff1740404b860b9b724f30538206b67>>
  */
 
 /**
@@ -152,6 +152,8 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun fuseboxEnabledRelease(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun fuseboxFrameRecordingEnabled(): Boolean
+
   @DoNotStrip @JvmStatic public external fun fuseboxNetworkInspectionEnabled(): Boolean
 
   @DoNotStrip @JvmStatic public external fun hideOffscreenVirtualViewsOnIOS(): Boolean

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsDefaults.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<89cd07b543fc079341bb3a5d90e50d13>>
+ * @generated SignedSource<<0a871795464dbf64e4a533b5694f55e6>>
  */
 
 /**
@@ -147,6 +147,8 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun fuseboxEnabledRelease(): Boolean = false
 
+  override fun fuseboxFrameRecordingEnabled(): Boolean = false
+
   override fun fuseboxNetworkInspectionEnabled(): Boolean = true
 
   override fun hideOffscreenVirtualViewsOnIOS(): Boolean = false

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsLocalAccessor.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<e82235d73386509fc2378a5b8e4b2cfa>>
+ * @generated SignedSource<<786ff3e6041a60ec2816d14b34fba436>>
  */
 
 /**
@@ -86,6 +86,7 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
   private var fixYogaFlexBasisFitContentInMainAxisCache: Boolean? = null
   private var fuseboxAssertSingleHostStateCache: Boolean? = null
   private var fuseboxEnabledReleaseCache: Boolean? = null
+  private var fuseboxFrameRecordingEnabledCache: Boolean? = null
   private var fuseboxNetworkInspectionEnabledCache: Boolean? = null
   private var hideOffscreenVirtualViewsOnIOSCache: Boolean? = null
   private var overrideBySynchronousMountPropsAtMountingAndroidCache: Boolean? = null
@@ -733,6 +734,16 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
     return cached
   }
 
+  override fun fuseboxFrameRecordingEnabled(): Boolean {
+    var cached = fuseboxFrameRecordingEnabledCache
+    if (cached == null) {
+      cached = currentProvider.fuseboxFrameRecordingEnabled()
+      accessedFeatureFlags.add("fuseboxFrameRecordingEnabled")
+      fuseboxFrameRecordingEnabledCache = cached
+    }
+    return cached
+  }
+
   override fun fuseboxNetworkInspectionEnabled(): Boolean {
     var cached = fuseboxNetworkInspectionEnabledCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<e3051a7aec6e7da31a65eb2d58fcd64b>>
+ * @generated SignedSource<<7b7b3093a60d8b4f6d541998942f0f9f>>
  */
 
 /**
@@ -147,6 +147,8 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun fuseboxEnabledRelease(): Boolean
 
+  @DoNotStrip public fun fuseboxFrameRecordingEnabled(): Boolean
+
   @DoNotStrip public fun fuseboxNetworkInspectionEnabled(): Boolean
 
   @DoNotStrip public fun hideOffscreenVirtualViewsOnIOS(): Boolean

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/runtime/ReactHostImpl.kt

@@ -1565,16 +1565,18 @@ public class ReactHostImpl(
           when (state) {
             TracingState.ENABLED_IN_BACKGROUND_MODE,
             TracingState.ENABLED_IN_CDP_MODE -> {
-              val observer =
-                  FrameTimingsObserver(
-                      _screenshotsEnabled,
-                      { frameTimingsSequence ->
-                        inspectorTarget.recordFrameTimings(frameTimingsSequence)
-                      },
-                  )
-              observer.setCurrentWindow(currentActivity?.window)
-              observer.start()
-              frameTimingsObserver = observer
+              if (InspectorFlags.getFrameRecordingEnabled()) {
+                val observer =
+                    FrameTimingsObserver(
+                        _screenshotsEnabled,
+                        { frameTimingsSequence ->
+                          inspectorTarget.recordFrameTimings(frameTimingsSequence)
+                        },
+                    )
+                observer.setCurrentWindow(currentActivity?.window)
+                observer.start()
+                frameTimingsObserver = observer
+              }
             }
             TracingState.DISABLED -> {
               frameTimingsObserver?.stop()

packages/react-native/ReactAndroid/src/main/jni/react/devsupport/JInspectorFlags.cpp

@@ -21,6 +21,12 @@ bool JInspectorFlags::getIsProfilingBuild(jni::alias_ref<jclass> /*unused*/) {
   return inspectorFlags.getIsProfilingBuild();
 }
 
+bool JInspectorFlags::getFrameRecordingEnabled(
+    jni::alias_ref<jclass> /*unused*/) {
+  auto& inspectorFlags = InspectorFlags::getInstance();
+  return inspectorFlags.getFrameRecordingEnabled();
+}
+
 void JInspectorFlags::registerNatives() {
   javaClassLocal()->registerNatives({
       makeNativeMethod("getFuseboxEnabled", JInspectorFlags::getFuseboxEnabled),
@@ -29,6 +35,11 @@ void JInspectorFlags::registerNatives() {
       makeNativeMethod(
           "getIsProfilingBuild", JInspectorFlags::getIsProfilingBuild),
   });
+  javaClassLocal()->registerNatives({
+      makeNativeMethod(
+          "getFrameRecordingEnabled",
+          JInspectorFlags::getFrameRecordingEnabled),
+  });
 }
 
 } // namespace facebook::react::jsinspector_modern

packages/react-native/ReactAndroid/src/main/jni/react/devsupport/JInspectorFlags.h

@@ -20,6 +20,7 @@ class JInspectorFlags : public jni::JavaClass<JInspectorFlags> {
 
   static bool getFuseboxEnabled(jni::alias_ref<jclass> /*unused*/);
   static bool getIsProfilingBuild(jni::alias_ref<jclass> /*unused*/);
+  static bool getFrameRecordingEnabled(jni::alias_ref<jclass> /*unused*/);
 
   static void registerNatives();