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 d2a97a1883c57e753c000baf06454d6e8b0f9156..49816dd5026b684a31daea037be14f6ab51dbb42 100644
--- a/chrome/browser/managed_mode/managed_mode_browsertest.cc
+++ b/chrome/browser/managed_mode/managed_mode_browsertest.cc
@@ -588,6 +588,7 @@ 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,
@@ -613,4 +614,6 @@ IN_PROC_BROWSER_TEST_F(ManagedModeBlockModeTest,
   EXPECT_TRUE(web_contents_modal_dialog_manager->IsShowingDialog());
 }
 
+#endif  // OS_CHROMEOS
+
 }  // namespace