This component provides a unified model of user language which will serve as the single source of truth for other components. Language is implemented as a layered component (https://sites.google.com/a/chromium.org/dev/developers/design-documents/layered-components-design) to enable it to be shared cleanly on iOS. This component has the following structure: core/: shared code that does not depend on src/content or src/ios. content/: Driver for the shared code based on the content layer. browser/: Browser process code. renderer/: Renderer process code. common/: Code shared by the browser and the renderer. ios/: Driver for the shared code based on src/ios.