Pass Physical Web metadata through a struct

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"
@@ skipping 13 matching lines @@
 
   // 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;
+  std::unique_ptr<base::ListValue> GetMetadataListValue() override;

[mattreynolds, 2016/12/12 19:41:29]

(should be GetMetadata)

Also, IOSChromePhysicalWebDataSource needs an implementation of GetMetadataList
(I think it's fine for it to be empty for now)

 
   // 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_;
 
   DISALLOW_COPY_AND_ASSIGN(IOSChromePhysicalWebDataSource);
 };
 
 #endif  // IOS_CHROME_COMMON_PHYSICAL_WEB_IOS_CHROME_PHYSICAL_WEB_DATA_SOURCE_H_