Record the initial state of the Physical Web at startup

ios/chrome/browser/physical_web/ios_chrome_physical_web_data_source.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 IOS_CHROME_BROWSER_PHYSICAL_WEB_IOS_CHROME_PHYSICAL_WEB_DATA_SOURCE_H_
 #define IOS_CHROME_BROWSER_PHYSICAL_WEB_IOS_CHROME_PHYSICAL_WEB_DATA_SOURCE_H_
 
 #include "base/macros.h"
 #import "base/mac/scoped_nsobject.h"
 #include "components/physical_web/data_source/physical_web_data_source_impl.h"
 
 namespace base {
 class ListValue;
 }
+class PrefService;
 
 @class PhysicalWebScanner;
+@class PhysicalWebInitialStateRecorder;
 
 // iOS implementation of PhysicalWebDataSource
 class IOSChromePhysicalWebDataSource
     : public physical_web::PhysicalWebDataSourceImpl {
  public:
-  IOSChromePhysicalWebDataSource();
+  IOSChromePhysicalWebDataSource(PrefService* pref_service);
   ~IOSChromePhysicalWebDataSource() override;
 
   // Starts scanning for Physical Web URLs. If |network_request_enabled| is
   // true, discovered URLs will be sent to a resolution service.
   void StartDiscovery(bool network_request_enabled) override;
 
   // Stops scanning for Physical Web URLs and clears cached URL content.
   void StopDiscovery() override;
 
   // Returns a list of resolved URLs and associated page metadata. If network
   // requests are disabled, the list will be empty.
   std::unique_ptr<base::ListValue> GetMetadata() override;
 
   // Returns boolean |true| if network requests are disabled and there are one
   // or more discovered URLs that have not been sent to the resolution service.
   bool HasUnresolvedDiscoveries() override;
 
  private:
   // Scanner for nearby Physical Web URL devices.
   base::scoped_nsobject<PhysicalWebScanner> scanner_;
 
+  // Utility for fetching initial application state for logging purposes.
+  base::scoped_nsobject<PhysicalWebInitialStateRecorder> initialStateRecorder_;
+
   DISALLOW_COPY_AND_ASSIGN(IOSChromePhysicalWebDataSource);
 };
 
 #endif  // IOS_CHROME_BROWSER_PHYSICAL_WEB_IOS_CHROME_PHYSICAL_WEB_DATA_SOURCE_H_