Add navigation client lib for convenience

services/navigation/public/cpp/view_delegate.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 SERVICES_NAVIGATION_PUBLIC_CPP_VIEW_DELEGATE_H_
+#define SERVICES_NAVIGATION_PUBLIC_CPP_VIEW_DELEGATE_H_
+
+#include <string>
+
+class GURL;
+namespace gfx {
+class Rect;
+}
+
+namespace navigation {
+
+class ViewDelegate {
+ public:
+  virtual ~ViewDelegate() {}
+
+  virtual void LoadingStateChanged(bool is_loading) {}
+
+  virtual void NavigationStateChanged(const GURL& url,
+                                      const std::string& title,
+                                      bool can_go_back,
+                                      bool can_go_forward) {}
+
+  virtual void LoadProgressChanged(double progress) {}
+
+  virtual void UpdateHoverURL(const GURL& url) {}
+
+  virtual void ViewCreated(mojom::ViewPtr view,
+                           mojom::ViewClientRequest request,
+                           bool is_popup,
+                           const gfx::Rect& initial_bounds,
+                           bool is_user_gesture) {}
+  
+  virtual void Close() {}
+};
+
+}  // namespace navigation
+
+#endif  // SERVICES_NAVIGATION_PUBLIC_CPP_VIEW_DELEGATE_H_