SplitSettings: Port settings main page tests for OS settings page

Ports most of //c/test/data/webui/settings/settings_main_test.js to
the OS settings page.

Initializes CrOncStrings in the test because the test does not load
os_settings_ui.js, but the global must exist for the network page.

Adds assertions for CrOncStrings to make this failure more obvious
in the future (otherwise the error is just "reading property of
undefined" without a useful line number).

Bug: 967910
Test: browser_tests

Change-Id: Ia86483a2c204d82387a6c771a02075f76acc3681
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1642249Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#666308}

chrome/browser/resources/settings/internet_page/network_summary_item.html

@@ -2,6 +2,7 @@
 
 <link rel="import" href="chrome://resources/cr_components/chromeos/network/network_siminfo.html">
 <link rel="import" href="chrome://resources/cr_elements/chromeos/network/cr_network_icon.html">
+<link rel="import" href="chrome://resources/cr_elements/chromeos/network/cr_onc_types.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_icon_button/cr_icon_button.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_toggle/cr_toggle.html">
 <link rel="import" href="chrome://resources/cr_elements/policy/cr_policy_indicator.html">

chrome/browser/resources/settings/internet_page/network_summary_item.js

@@ -367,6 +367,7 @@ Polymer({
    * @private
    */
   getTitleText_: function() {
+    assert(CrOncStrings);
     return this.networkTitleText ||
         CrOncStrings['OncType' + this.activeNetworkState.Type];
   },

chrome/test/data/webui/settings/chromeos/os_settings_browsertest.js

@@ -70,6 +70,29 @@ TEST_F('OSSettingsSmbPageTest', 'MAYBE_All', function() {
   mocha.run();
 });
 
+// Test fixture for the main settings page.
+// eslint-disable-next-line no-var
+var OSSettingsMainTest = class extends OSSettingsBrowserTest {
+  /** @override */
+  get browsePreload() {
+    return super.browsePreload +
+        'chromeos/os_settings_main/os_settings_main.html';
+  }
+
+  /** @override */
+  get extraLibraries() {
+    return super.extraLibraries.concat([
+      BROWSER_SETTINGS_PATH + 'test_util.js',
+      BROWSER_SETTINGS_PATH + '../test_browser_proxy.js',
+      'os_settings_main_test.js',
+    ]);
+  }
+};
+
+TEST_F('OSSettingsMainTest', 'MAYBE_All', function() {
+  mocha.run();
+});
+
 // Tests for the side-nav menu.
 // eslint-disable-next-line no-var
 var OSSettingsMenuTest = class extends OSSettingsBrowserTest {

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

@@ -475,6 +475,7 @@ CrOnc.getNetworkName = function(properties) {
   const name = CrOnc.getStateOrActiveString(properties.Name);
   const type = CrOnc.getStateOrActiveString(properties.Type);
   if (!name) {
+    assert(CrOncStrings);
     return CrOncStrings['OncType' + type];
   }
   if (type == 'VPN' && properties.VPN) {