# Chrome OS This directory contains low-level support for Chrome running on Chrome OS. The [Lacros project](go/lacros) is in the process of extracting the browser-functionality into a separate binary. This introduces the following terminology and rules: * ash-chrome: The new name of the legacy "chrome" binary. It contains system UI and the current/legacy web browser. Code that is only used by ash-chrome should eventually be moved to //chromeos/ash, have an _ash suffix in the filename, or have a (grand-)parent directory named /ash/. * lacros-chrome: The name of the new, standalone web-browser binary. Code that is only used by lacros-chrome should have a _lacros suffix in the filename, or have a (grand-)parent directory named /lacros/. * crosapi: The term "crosapi" is short for ChromeOS API. Ash-chrome implements the API, and lacros-chrome is the only consumer. * chromeos: The term "chromeos" refers to code that is shared by binaries targeting the chromeos platform or using the chromeos toolchain. Code that is shared by ash-chrome and lacros-chrome should have a _chromeos suffix in the filename, or have a (grand-)parent directory named /chromeos/. * Exception: The exception to the rule is //chrome/browser/chromeos. Following existing conventions in //chrome, the directory *should* refer to lacros-chrome. However, this would involve a massive and otherwise unnecessary refactor. //chrome/browser/chromeos will continue to contain code that is only used by ash-chrome. //chrome/browser/lacros will contain code used only by lacros-chrome. See [this document](go/lacros-code-layout) for more details. Many subdirectories contain Chrome-style C++ wrappers around operating system components. For example, //chromeos/dbus contains wrappers around the D-Bus interfaces to system daemons like the network configuration manager (shill). Most other directories contain low-level utility code. There are two exceptions: - //chromeos/services contains mojo services that were not considered sufficiently general to live in top-level //services and that, at the same time, are shared between ash-chrome and lacros-chrome. In case of an ash-chrome only mojo service, please use //chromeos/ash/services instead. - //chromeos/components contains C++ components that were not considered sufficiently general to live in top-level //components. Note, //chromeos does not contain any user-facing UI code, and hence it has "-ui" in its DEPS. The contents of //chromeos should also not depend on //chrome or //content.