Add BlimpContents[,Observer] and BlimpNavigationController

blimp/client/core/blimp_navigation_controller_impl.h

Index: blimp/client/core/blimp_navigation_controller_impl.h
diff --git a/blimp/client/core/blimp_navigation_controller_impl.h b/blimp/client/core/blimp_navigation_controller_impl.h
new file mode 100644
index 0000000000000000000000000000000000000000..b62ed25a1f47a4d05957f2e271298234ebad4789
--- /dev/null
+++ b/blimp/client/core/blimp_navigation_controller_impl.h
@@ -0,0 +1,54 @@
+// 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_CORE_BLIMP_NAVIGATION_CONTROLLER_IMPL_H_
+#define BLIMP_CLIENT_CORE_BLIMP_NAVIGATION_CONTROLLER_IMPL_H_
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "blimp/client/core/public/blimp_navigation_controller.h"
+#include "url/gurl.h"
+
+namespace blimp {
+namespace client {
+
+class BlimpContentsObserver;
+class BlimpNavigationControllerDelegate;
+
+// BlimpContentsImpl is the implementation of the core class in
+// //blimp/client/core, the BlimpContents.
+// The BlimpNavigationControllerImpl is the implementation part of
+// BlimpNavigationController. It maintains the back-forward list for a
+// BlimpContentsImpl and manages all navigation within that list.
+class BlimpNavigationControllerImpl : public BlimpNavigationController {
+ public:
+  explicit BlimpNavigationControllerImpl(
+      BlimpNavigationControllerDelegate* delegate);
+  ~BlimpNavigationControllerImpl() override;
+
+  // BlimpNavigationController implementation.
+  void LoadURL(const GURL& url) override;
+  const GURL& GetURL() override;
+
+ private:
+  void NotifyDelegateURLLoaded(const GURL& url);
+
+  // The delegate contains functionality required for the navigation controller
+  // to function correctly. It is also invoked on relevant state changes of the
+  // navigation controller.
+  BlimpNavigationControllerDelegate* delegate_;
+
+  // The currently active URL.
+  GURL current_url_;
+
+  // TODO(shaktisahu): Remove this after integration with NavigationFeature.
+  base::WeakPtrFactory<BlimpNavigationControllerImpl> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(BlimpNavigationControllerImpl);
+};
+
+}  // namespace client
+}  // namespace blimp
+
+#endif  // BLIMP_CLIENT_CORE_BLIMP_NAVIGATION_CONTROLLER_IMPL_H_