Use GURLs in Physical Web data source

components/physical_web/data_source/physical_web_data_source_impl.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 COMPONENTS_PHYSICAL_WEB_DATA_SOURCE_PHYSICAL_WEB_DATA_SOURCE_IMPL_H_
 #define COMPONENTS_PHYSICAL_WEB_DATA_SOURCE_PHYSICAL_WEB_DATA_SOURCE_IMPL_H_
 
 #include "base/observer_list.h"
 #include "components/physical_web/data_source/physical_web_data_source.h"
 
+class GURL;
+
 namespace physical_web {
 
 class PhysicalWebListener;
 
 class PhysicalWebDataSourceImpl : public PhysicalWebDataSource {
  public:
   PhysicalWebDataSourceImpl();
   ~PhysicalWebDataSourceImpl() override;
 
   // Register for changes to Physical Web URLs and associated page metadata.
   void RegisterListener(PhysicalWebListener* physical_web_listener) override;
 
   // Unregister for changes to Physical Web URLs and associated page metadata.
   void UnregisterListener(PhysicalWebListener* physical_web_listener) override;
 
   // Notify all registered listeners that a URL has been found.
-  void NotifyOnFound(const std::string& url);
+  void NotifyOnFound(const GURL& url);
 
   // Notify all registered listeners that a URL has been lost.
-  void NotifyOnLost(const std::string& url);
+  void NotifyOnLost(const GURL& url);
 
   // Notify all registered listeners that a distance has changed for a URL.
-  void NotifyOnDistanceChanged(const std::string& url,
+  void NotifyOnDistanceChanged(const GURL& url,
                                double distance_estimate);
 
  private:
   base::ObserverList<PhysicalWebListener> observer_list_;
 };
 
 }  // namespace physical_web
 
 #endif  // COMPONENTS_PHYSICAL_WEB_DATA_SOURCE_PHYSICAL_WEB_DATA_SOURCE_IMPL_H_