Pass Physical Web metadata through a struct

ios/chrome/browser/ui/webui/physical_web_ui.cc

 // 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.
 
 #include "ios/chrome/browser/ui/webui/physical_web_ui.h"
 
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/user_metrics.h"
@@ skipping 60 matching lines @@
   web_ui()->RegisterMessageCallback(
       physical_web_ui::kPhysicalWebItemClicked,
       base::Bind(&PhysicalWebDOMHandler::HandlePhysicalWebItemClicked,
                  base::Unretained(this)));
 }
 
 void PhysicalWebDOMHandler::HandleRequestNearbyURLs(
     const base::ListValue* args) {
   base::DictionaryValue results;
 
-  std::unique_ptr<base::ListValue> metadata =
-      GetApplicationContext()->GetPhysicalWebDataSource()->GetMetadata();
+  std::unique_ptr<base::ListValue> metadata = GetApplicationContext()
+                                                  ->GetPhysicalWebDataSource()
+                                                  ->GetMetadataListValue();
 
   // Add item indices. When an item is selected, the index of the selected item
   // is recorded in a UMA histogram.
   for (size_t i = 0; i < metadata->GetSize(); i++) {
     base::DictionaryValue* metadata_item = NULL;
     metadata->GetDictionary(i, &metadata_item);
     metadata_item->SetInteger(physical_web_ui::kIndex, i);
   }
 
   results.Set(physical_web_ui::kMetadata, metadata.release());
@@ skipping 37 matching lines @@
   PhysicalWebDOMHandler* handler = new PhysicalWebDOMHandler();
   web_ui->AddMessageHandler(handler);
 
   web::WebUIIOSDataSource::Add(ios::ChromeBrowserState::FromWebUIIOS(web_ui),
                                CreatePhysicalWebUIDataSource());
 
   base::RecordAction(base::UserMetricsAction("PhysicalWeb.WebUI.Open"));
 }
 
 PhysicalWebUI::~PhysicalWebUI() {}