Split //blimp/client/core to relevant parts.

blimp/client/public/blimp_navigation_controller.h

-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef BLIMP_CLIENT_PUBLIC_BLIMP_NAVIGATION_CONTROLLER_H_
-#define BLIMP_CLIENT_PUBLIC_BLIMP_NAVIGATION_CONTROLLER_H_
-
-#include "base/macros.h"
-#include "url/gurl.h"
-
-namespace blimp {
-namespace client {
-
-class BlimpContentsObserver;
-
-// The BlimpNavigationController maintains the back-forward list for a
-// BlimpContents and manages all navigation within that list.
-//
-// Each BlimpNavigationController belongs to one BlimpContents, and each
-// BlimpContents has exactly one BlimpNavigationController.
-class BlimpNavigationController {
- public:
-  virtual ~BlimpNavigationController() = default;
-
-  // Calls to LoadURL informs the engine that it should start navigating to the
-  // provided |url|.
-  virtual void LoadURL(const GURL& url) = 0;
-
-  // Retrieves the URL of the currently selected item in the navigation list.
-  virtual const GURL& GetURL() = 0;
-
- protected:
-  BlimpNavigationController() {}
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(BlimpNavigationController);
-};
-
-}  // namespace client
-}  // namespace blimp
-
-#endif  // BLIMP_CLIENT_PUBLIC_BLIMP_NAVIGATION_CONTROLLER_H_