Associate a scan mode with Physical Web listeners

components/physical_web/data_source/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 COMPONENTS_PHYSICAL_WEB_DATA_SOURCE_PHYSICAL_WEB_DATA_SOURCE_H_
 #define COMPONENTS_PHYSICAL_WEB_DATA_SOURCE_PHYSICAL_WEB_DATA_SOURCE_H_
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/time/time.h"
 #include "url/gurl.h"
 
 namespace physical_web {
 
 class PhysicalWebListener;
 
+// Enum describing scan policies.
+enum ScanMode {
+  // Request no particular scan policy.  Opportunistic listeners will receive
+  // notifications when any other listener requests a scan.
+  OPPORTUNISTIC = 0,
+  // Request a scan that runs occassionally, even when Chrome is not in the
+  // foreground.  Android only.
+  BACKGROUND_INTERMITTENT = 1 << 0,
+};
+
 // Metadata struct for associating data with Physical Web URLs.
 struct Metadata {
   Metadata();
   Metadata(const Metadata& other);
   ~Metadata();
   // The URL broadcasted by the beacon and scanned by the client device.
   // REQUIRED
   GURL scanned_url;
   // The URL that the scanned_url redirects to.
   // This is the URL that users should be directed to.
@@ skipping 53 matching lines @@
   virtual std::unique_ptr<MetadataList> GetMetadataList() = 0;
 
   // 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.
   // The method can be called at any time to check for unresolved discoveries.
   // If discovery is inactive or network requests are enabled, it will always
   // return false.
   virtual bool HasUnresolvedDiscoveries() = 0;
 
   // Register for changes to Physical Web URLs and associated page metadata.
-  virtual void RegisterListener(PhysicalWebListener* physical_web_listener) = 0;
+  // This may be called multiple times in order to change the associated scan
+  // mode.
+  virtual void RegisterListener(PhysicalWebListener* physical_web_listener,
+      ScanMode scan_mode) = 0;
 
   // Unregister for changes to Physical Web URLs and associated page metadata.
   virtual void UnregisterListener(
       PhysicalWebListener* physical_web_listener) = 0;
 };
 
 }  // namespace physical_web
 
 #endif  // COMPONENTS_PHYSICAL_WEB_DATA_SOURCE_PHYSICAL_WEB_DATA_SOURCE_H_