[WebUI] Disable 3 flaky tests on ChromiumOS dbg (timeouts)

chrome/test/data/webui/settings/cr_settings_browsertest.js

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /** @fileoverview Runs the Polymer Settings tests. */
 
 /** @const {string} Path to source root. */
 var ROOT_PATH = '../../../../../';
 
 // Polymer BrowserTest fixture.
@@ skipping 1118 matching lines @@
 CrSettingsNonExistentRouteTest.prototype = {
   __proto__: CrSettingsBrowserTest.prototype,
 
   /** @override */
   browsePreload: 'chrome://md-settings/non/existent/route',
 
   /** @override */
   runAccessibilityChecks: false,
 };
 
-TEST_F('CrSettingsNonExistentRouteTest', 'All', function() {
+// Failing on ChromiumOS dbg. https://crbug.com/709442
+GEN('#if defined(OS_CHROMEOS) && !defined(NDEBUG)');
+GEN('#define MAYBE_All DISABLED_All');
+GEN('#else');
+GEN('#define MAYBE_All All');
+GEN('#endif');
+TEST_F('CrSettingsNonExistentRouteTest', 'MAYBE_All', function() {
   suite('NonExistentRoutes', function() {
     test('redirect to basic', function() {
       assertEquals(settings.Route.BASIC, settings.getCurrentRoute());
       assertEquals('/', location.pathname);
     });
   });
   mocha.run();
 });
 
 /**
@@ skipping 266 matching lines @@
   extraLibraries: CrSettingsBrowserTest.prototype.extraLibraries.concat([
     'test_browser_proxy.js',
     'test_extension_control_browser_proxy.js',
     'extension_controlled_indicator_tests.js',
   ]),
 };
 
 TEST_F('CrSettingsExtensionControlledIndicatorTest', 'All', function() {
   mocha.run();
 });