Don't allow elevation for CHROME_OS.

chrome/browser/managed_mode/managed_mode_browsertest.cc

Index: chrome/browser/managed_mode/managed_mode_browsertest.cc
diff --git a/chrome/browser/managed_mode/managed_mode_browsertest.cc b/chrome/browser/managed_mode/managed_mode_browsertest.cc
index 644655253c76857f9fc161e0a32ceb1dd08d6a17..ec718e7f34596054e6e0a14c2e6008a08fa191e0 100644
--- a/chrome/browser/managed_mode/managed_mode_browsertest.cc
+++ b/chrome/browser/managed_mode/managed_mode_browsertest.cc
@@ -598,6 +598,7 @@ IN_PROC_BROWSER_TEST_F(ManagedModeBlockModeTest,
                 "www.new-example.com"));
 }
 
+#if !defined(OS_CHROMEOS)
 // Now check that the passphrase dialog is shown when a passphrase is specified
 // and the user clicks on the preview button.
 IN_PROC_BROWSER_TEST_F(ManagedModeBlockModeTest,
@@ -623,4 +624,6 @@ IN_PROC_BROWSER_TEST_F(ManagedModeBlockModeTest,
   EXPECT_TRUE(web_contents_modal_dialog_manager->IsShowingDialog());
 }
 
+#endif  // OS_CHROMEOS
+
 }  // namespace