Fix segfault when getting network details.

Segfault occurs in internet_options_handler.cc when accessing a
non-existent policy. This was introduced in https://crrev.com/427903004.

Please note: http://imgur.com/sD3vz0W.jpg

BUG=403111
R=pneubeck@chromium.org
TBR=stevenjb@chromium.org

Review URL: https://codereview.chromium.org/470433002

Cr-Commit-Position: refs/heads/master@{#289201}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289201 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/webui/options/chromeos/internet_options_handler.cc

@@ -1374,13 +1374,17 @@ void InternetOptionsHandler::PopulateDictionaryDetailsCallback(
     scoped_ptr<base::Value> auto_connect_value(
         new base::FundamentalValue(auto_connect));
     ::onc::ONCSource auto_connect_onc_source = onc_source;
+
+    DCHECK_EQ(onc == NULL, onc_source == ::onc::ONC_SOURCE_NONE);
     bool auto_connect_recommended =
         auto_connect_onc_source != ::onc::ONC_SOURCE_NONE &&
         onc::IsRecommendedValue(onc, onc_path_to_auto_connect);
-    // |auto_connect_default_value| will contain either a recommended value
-    // if |auto_connect_recommended| is true, or an enforced value otherwise.
+    // If a policy exists, |auto_connect_default_value| will contain either a
+    // recommended value (if |auto_connect_recommended| is true) or an enforced
+    // value (if |auto_connect_recommended| is false).
     const base::Value* auto_connect_default_value = NULL;
-    onc->Get(onc_path_to_auto_connect, &auto_connect_default_value);
+    if (onc)
+      onc->Get(onc_path_to_auto_connect, &auto_connect_default_value);
 
     // Autoconnect can be controlled by the GlobalNetworkConfiguration of the
     // ONC policy.