Reduce usage of FOR_EACH_OBSERVER macro in components/

components/proximity_auth/proximity_monitor_impl.cc

Index: components/proximity_auth/proximity_monitor_impl.cc
diff --git a/components/proximity_auth/proximity_monitor_impl.cc b/components/proximity_auth/proximity_monitor_impl.cc
index 793062bd48b9d4f71b1bb2fb72aa034bbd85330f..cf908b47e9b53e5f336cea7d07133be7f445c442 100644
--- a/components/proximity_auth/proximity_monitor_impl.cc
+++ b/components/proximity_auth/proximity_monitor_impl.cc
@@ -221,8 +221,8 @@ void ProximityMonitorImpl::OnConnectionInfo(
 
 void ProximityMonitorImpl::ClearProximityState() {
   if (is_active_ && remote_device_is_in_proximity_) {
-    FOR_EACH_OBSERVER(ProximityMonitorObserver, observers_,
-                      OnProximityStateChanged());
+    for (auto& observer : observers_)
+      observer.OnProximityStateChanged();
   }
 
   remote_device_is_in_proximity_ = false;
@@ -273,8 +273,8 @@ void ProximityMonitorImpl::CheckForProximityStateChange() {
     PA_LOG(INFO) << "[Proximity] Updated proximity state: "
                  << (is_now_in_proximity ? "proximate" : "distant");
     remote_device_is_in_proximity_ = is_now_in_proximity;
-    FOR_EACH_OBSERVER(ProximityMonitorObserver, observers_,
-                      OnProximityStateChanged());
+    for (auto& observer : observers_)
+      observer.OnProximityStateChanged();
   }
 }