Associate a scan mode with Physical Web listeners

components/physical_web/data_source/physical_web_data_source_impl.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 "base/observer_list.h"
 #include "components/physical_web/data_source/physical_web_data_source.h"
 #include "components/physical_web/data_source/physical_web_data_source_impl.h"
 #include "components/physical_web/data_source/physical_web_listener.h"
 
 namespace physical_web {
 
 PhysicalWebDataSourceImpl::PhysicalWebDataSourceImpl() {}
 
 PhysicalWebDataSourceImpl::~PhysicalWebDataSourceImpl() {}
 
 void PhysicalWebDataSourceImpl::RegisterListener(
-    PhysicalWebListener* physical_web_listener) {
-  observer_list_.AddObserver(physical_web_listener);
+    PhysicalWebListener* physical_web_listener, ScanMode scan_mode) {
+  if (!observer_list_.HasObserver(physical_web_listener)) {
+    observer_list_.AddObserver(physical_web_listener);
+  }
+  scan_modes_[physical_web_listener] = scan_mode;
 }
 
 void PhysicalWebDataSourceImpl::UnregisterListener(
     PhysicalWebListener* physical_web_listener) {
+  if (!observer_list_.HasObserver(physical_web_listener)) return;
+
   observer_list_.RemoveObserver(physical_web_listener);
+  scan_modes_.erase(scan_modes_.find(physical_web_listener));

[vitaliii, 2017/03/24 09:41:49]

Nit: unordered_map.erase seems to accept key type as a parameter (see (3) in
http://en.cppreference.com/w/cpp/container/unordered_map/erase), so find here
seems redundant.

 }
 
 void PhysicalWebDataSourceImpl::NotifyOnFound(const GURL& url) {
   for (PhysicalWebListener& observer : observer_list_)
     observer.OnFound(url);
 }
 
 void PhysicalWebDataSourceImpl::NotifyOnLost(const GURL& url) {
   for (PhysicalWebListener& observer : observer_list_)
     observer.OnLost(url);
 }
 
 void PhysicalWebDataSourceImpl::NotifyOnDistanceChanged(
     const GURL& url,
     double distance_estimate) {
   for (PhysicalWebListener& observer : observer_list_)
     observer.OnDistanceChanged(url, distance_estimate);
 }
 
 }  // namespace physical_web