Associate a scan mode with Physical Web listeners

components/physical_web/data_source/physical_web_data_source_impl.cc

Index: components/physical_web/data_source/physical_web_data_source_impl.cc
diff --git a/components/physical_web/data_source/physical_web_data_source_impl.cc b/components/physical_web/data_source/physical_web_data_source_impl.cc
index 86b4c185a14c34328c6e4c36de6b023f0730e925..b5f03558c15bd9866dbf8ea5457d0253283b5a2d 100644
--- a/components/physical_web/data_source/physical_web_data_source_impl.cc
+++ b/components/physical_web/data_source/physical_web_data_source_impl.cc
@@ -14,13 +14,19 @@ 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) {