In the long term, we think of Chromium as a tabbed window manager or shell for the web rather than a browser application. We avoid putting things into our UI in the same way you would hope that Apple and Microsoft would avoid putting things into the standard window frames of applications on their operating systems. The tab is our equivalent of a desktop application's title bar; the frame containing the tabs is a convenient mechanism for managing groups of those applications. In future, there may be other tab types that do not host the normal browser toolbar, explains a document about Chrome's user experience.
Google Chrome is built for web applications that have their own menus, keyword shortcuts and status bars. Chrome comes with intelligent defaults to minimize the interaction with the browser. The settings dialog doesn't include many options available in other browsers and the team hopes to "reduce the number of options further". The lack of customization is not a good news for advanced users, but normal users might appreciate the simplicity of the interface.
Source:→ Google System