1KeyedService is a layered component
2(https://sites.google.com/a/chromium.org/dev/developers/design-documents/layered-components-design)
3to enable it to be shared cleanly on iOS.
4
5This component has the following structure:
6
7- core/: shared code that does not depend on src/content/ or src/ios/
8- content/: Code based on the content layer.
9- ios/: Code based on src/ios.
10