Component used: Window
Version used: 1.0.0-beta02
Devices/Android versions reproduced on: Android 11 (real and emulator)

Essentially the logic is setup a sample project with a fragment and invoke the windowInfoRepository() method with an activity. That causes the ExtensionWindowBackend.globalInstance to hold on to the activity's context. Perhaps using the application context would be better, but I don't know how the context is used.

For example I am using Kotlin and only do the following to get the window metrics to replace deprecated code in Android 12.

val metrics = activity?.windowInfoRepository()?.currentWindowMetrics?.firstOrNull()?.bounds

Stack trace of the leak:

┬───
│ GC Root: Input or output parameters in native code
│
├─ okio.AsyncTimeout class
│ Leaking: NO (PathClassLoader↓ is not leaking and a class is never leaking)
│ ↓ static AsyncTimeout.$class$classLoader
├─ dalvik.system.PathClassLoader instance
│ Leaking: NO (ExtensionWindowBackend↓ is not leaking and A ClassLoader is
│ never leaking)
│ ↓ ClassLoader.runtimeInternalObjects
├─ java.lang.Object[] array
│ Leaking: NO (ExtensionWindowBackend↓ is not leaking)
│ ↓ Object[].[7701]
├─ androidx.window.layout.ExtensionWindowBackend class
│ Leaking: NO (a class is never leaking)
│ ↓ static ExtensionWindowBackend.globalInstance
│ ~~~~~~~~~~~~~~
├─ androidx.window.layout.ExtensionWindowBackend instance
│ Leaking: UNKNOWN
│ Retaining 125.0 kB in 2848 objects
│ ↓ ExtensionWindowBackend.windowExtension
│ ~~~~~~~~~~~~~~~
├─ androidx.window.layout.SidecarCompat instance
│ Leaking: UNKNOWN
│ Retaining 124.9 kB in 2844 objects
│ ↓ SidecarCompat.sidecar
│ ~~~~~~~
├─ androidx.window.sidecar.SettingsSidecarImpl instance
│ Leaking: UNKNOWN
│ Retaining 124.6 kB in 2832 objects
│ mContext instance of com.example.MyActivity with
│ mDestroyed = true
│ ↓ SettingsSidecarImpl.mContext
│ ~~~~~~~~
╰→ com.example.MyActivity instance
Leaking: YES (ObjectWatcher was watching this because com.example.MyActivity
received Activity#onDestroy() callback and
Activity#mDestroyed is true)
Retaining 115.4 kB in 2676 objects
key = 169cb8aa-ce65-4d85-ad39-a03daaad93f7
watchDurationMillis = 5190
retainedDurationMillis = 190
mApplication instance of com.example.Application
mBase instance of androidx.appcompat.view.ContextThemeWrapper

METADATA

Build.VERSION.SDK_INT: 30
Build.MANUFACTURER: Google
LeakCanary version: 2.7
App process name: com.example.debug
Count of retained yet cleared: 4 KeyedWeakReference instances
Stats: LruCache[maxSize=3000,hits=9130,misses=169317,hitRate=5%]
RandomAccess[bytes=9274118,reads=169317,travel=111728236112,range=42477374,size=
51517143]
Heap dump reason: 18 retained objects, app is visible
Analysis duration: 86480 ms