1Signin is in the process of becoming 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
5When this process is complete, this component will have the following structure:
6
7- core/: shared code that does not depend on src/content/ or src/ios/
8- content/: Driver for the shared code based on the content layer.
9- ios/: Driver for the shared code based on src/ios.
10