Network config: Elim bogus profile path unknown errors

Currently calls to FindPolicyByGuidAndProfile produce an error when
called with an empty profile path. There are several places where this
can occur, but we recently added one to the system tray UI:

https://chromium-review.googlesource.com/c/chromium/src/+/1101204/12/ash/system/network/network_list.cc#813

Rather than ensure that we test for an empty profile path everywhere
(which just indicates a non favorite/saved network), just return nullptr
with no error when the path is empty.

Bug: None
Change-Id: I692babc10ae2472e8fa5dbfef1c8be170cc841b2
Reviewed-on: https://chromium-review.googlesource.com/1149096Reviewed-by: Alexander Hendrich <hendrich@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Steven Bennetts <stevenjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577936}

chromeos/network/auto_connect_handler.cc

@@ -352,7 +352,6 @@ void AutoConnectHandler::DisconnectAndRemoveBlacklistedNetworks() {
       continue;
 
     const bool is_managed =
-        !network->profile_path().empty() && !network->guid().empty() &&
         managed_configuration_handler_->FindPolicyByGuidAndProfile(
             network->guid(), network->profile_path(), nullptr /* onc_source */);
     if (is_managed)
@@ -376,7 +375,6 @@ void AutoConnectHandler::DisconnectFromAllUnmanagedWiFiNetworks(
                                                false, false, 0, &networks);
   for (const NetworkState* network : networks) {
     const bool is_managed =
-        !network->profile_path().empty() && !network->guid().empty() &&
         managed_configuration_handler_->FindPolicyByGuidAndProfile(
             network->guid(), network->profile_path(), nullptr /* onc_source */);
     if (is_managed)

chromeos/network/managed_network_configuration_handler_impl.cc

@@ -778,16 +778,19 @@ ManagedNetworkConfigurationHandlerImpl::FindPolicyByGuidAndProfile(
     const std::string& guid,
     const std::string& profile_path,
     ::onc::ONCSource* onc_source) const {
+  if (profile_path.empty())
+    return nullptr;
+
   const NetworkProfile* profile =
       network_profile_handler_->GetProfileForPath(profile_path);
   if (!profile) {
     NET_LOG_ERROR("Profile path unknown:" + profile_path, guid);
-    return NULL;
+    return nullptr;
   }
 
   const Policies* policies = GetPoliciesForProfile(*profile);
   if (!policies)
-    return NULL;
+    return nullptr;
 
   const base::DictionaryValue* policy =
       GetByGUID(policies->per_network_config, guid);
@@ -816,7 +819,6 @@ bool ManagedNetworkConfigurationHandlerImpl::IsNetworkBlockedByPolicy(
 
   // Check if the network is managed. Managed networks are always allowed.
   bool is_managed =
-      !profile_path.empty() &&
       FindPolicyByGuidAndProfile(guid, profile_path, nullptr /* onc_source */);
   if (is_managed)
     return false;

chromeos/network/network_connection_handler_impl.cc

@@ -461,11 +461,9 @@ void NetworkConnectionHandlerImpl::VerifyConfiguredAndConnect(
   service_properties.GetStringWithoutPathExpansion(shill::kProfileProperty,
                                                    &profile);
   ::onc::ONCSource onc_source = onc::ONC_SOURCE_NONE;
-  const base::DictionaryValue* policy = nullptr;
-  if (!profile.empty()) {
-    policy = managed_configuration_handler_->FindPolicyByGuidAndProfile(
-        guid, profile, &onc_source);
-  }
+  const base::DictionaryValue* policy =
+      managed_configuration_handler_->FindPolicyByGuidAndProfile(guid, profile,
+                                                                 &onc_source);
 
   if (type == shill::kTypeWifi) {
     const base::Value* hex_ssid_value = service_properties.FindKeyOfType(