third_party/android_sdk/window_extensions/README.md
This library is not available as a prebuilt like other optional system
libraries in order to encourage clients to access it via the androidx.window
wrapper library. However, Chrome uses it directly in order to reduce the binary
size overhead of the wrapper library. Googlers, see: b/233785784.
As with other optional SDK libraries, these classes are not compiled in. They
are available at runtime through a system library loaded by the framework
when a <uses-library> tag exists in an app's AndroidManifest.xml (which is
added via manifest merging when depending on the GN target).
Not all devices have this optional library available. You can check if it's
available via org.chromium.window.WindowApiCheck#isAvailable().
Library documentation: https://source.android.com/docs/core/display/windowmanager-extensions
Library source code: https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:window/extensions/
Run update_sources.sh