Revert 150813 - Disable WebNavigationApiTest.Failures for flakiness.

Failing on the ChromiumOS Dbg Bots.

BUG=141497,139117
TEST=none
TBR=jochen

Review URL: https://chromiumcodereview.appspot.com/10837188

TBR=dalecurtis@google.com
Review URL: https://chromiumcodereview.appspot.com/10825315

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@151233 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/extensions/api/web_navigation/web_navigation_apitest.cc

@@ -424,11 +424,10 @@ IN_PROC_BROWSER_TEST_F(WebNavigationApiTest, SimpleLoad) {
       RunExtensionSubtest("webnavigation", "test_simpleLoad.html")) << message_;
 }
 
-//TODO(jochen): Flakily failing after http://crrev.com/150796.
-//IN_PROC_BROWSER_TEST_F(WebNavigationApiTest, Failures) {
-//  ASSERT_TRUE(
-//      RunExtensionSubtest("webnavigation", "test_failures.html")) << message_;
-//}
+IN_PROC_BROWSER_TEST_F(WebNavigationApiTest, Failures) {
+  ASSERT_TRUE(
+      RunExtensionSubtest("webnavigation", "test_failures.html")) << message_;
+}
 
 IN_PROC_BROWSER_TEST_F(WebNavigationApiTest, FilteredTest) {
   ASSERT_TRUE(