Network config: cr-network-select: Ensure connected network is default

Bug: 792865
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I403b8d512bb6d7c8d0e4c6947a8704544ef0f27a
Reviewed-on: https://chromium-review.googlesource.com/956312Reviewed-by: Alexander Alekseev <alemate@chromium.org>
Commit-Queue: Steven Bennetts <stevenjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#541940}

ui/webui/resources/cr_elements/chromeos/network/cr_network_select.js

@@ -153,28 +153,32 @@ Polymer({
       this.ensureCellularNetwork_(networkStates);
     this.networkStateList_ = networkStates;
     var defaultNetwork;
-    if (networkStates.length > 0) {
-      // Handle an edge case where Ethernet is connecting.
-      if (networkStates.length > 1 &&
-          networkStates[0].ConnectionState ==
-              CrOnc.ConnectionState.CONNECTING &&
-          networkStates[1].ConnectionState == CrOnc.ConnectionState.CONNECTED) {
-        defaultNetwork = networkStates[1];
-      } else {
-        defaultNetwork = networkStates[0];
+    for (var i = 0; i < networkStates.length; ++i) {
+      var state = networkStates[i];
+      if (state.ConnectionState == CrOnc.ConnectionState.CONNECTED) {
+        defaultNetwork = state;
+        break;
+      }
+      if (state.ConnectionState == CrOnc.ConnectionState.CONNECTING &&
+          !defaultNetwork) {
+        defaultNetwork = state;
+        // Do not break here in case a non WiFi network is connecting but a
+        // WiFi network is connected.
+      } else if (state.Type == CrOnc.Type.WI_FI) {
+        break;  // Non connecting or connected WiFI networks are always last.
       }
-    } else if (!this.defaultNetworkState_) {
-      return;  // No change
     }
-    if (defaultNetwork && this.defaultNetworkState_ &&
-        defaultNetwork.GUID == this.defaultNetworkState_.GUID &&
-        defaultNetwork.ConnectionState ==
-            this.defaultNetworkState_.ConnectionState) {
+    if ((!defaultNetwork && !this.defaultNetworkState_) ||
+        (defaultNetwork && this.defaultNetworkState_ &&
+         defaultNetwork.GUID == this.defaultNetworkState_.GUID &&
+         defaultNetwork.ConnectionState ==
+             this.defaultNetworkState_.ConnectionState)) {
       return;  // No change to network or ConnectionState
     }
-    this.defaultNetworkState_ =
+    this.defaultNetworkState_ = defaultNetwork ?
         /** @type {!CrOnc.NetworkStateProperties|undefined} */ (
-            Object.assign({}, defaultNetwork));
+            Object.assign({}, defaultNetwork)) :
+        undefined;
     this.fire('default-network-changed', defaultNetwork);
   },