Disable flaky test SamlTest.CredentialPassingAPI for Linux

chrome/browser/chromeos/login/saml/saml_browsertest.cc

 // Copyright 2014 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.
 
 #include <cstring>
 #include <memory>
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 455 matching lines @@
   std::string message;
   do {
     ASSERT_TRUE(message_queue.WaitForMessage(&message));
   } while (message != "\"GaiaLoaded\"");
 
   // Saml flow is gone.
   JsExpect("!$('gaia-signin').classList.contains('full-width')");
 }
 
 // Tests the sign-in flow when the credentials passing API is used.
-IN_PROC_BROWSER_TEST_F(SamlTest, CredentialPassingAPI) {
+//
+// Flaky. See http://crbug.com/659992
+#if defined(OS_LINUX)
+#define MAYBE_CredentialPassingAPI DISABLED_CredentialPassingAPI
+#else
+#define MAYBE_CredentialPassingAPI CredentialPassingAPI
+#endif
+IN_PROC_BROWSER_TEST_F(SamlTest, MAYBE_CredentialPassingAPI) {
   fake_saml_idp()->SetLoginHTMLTemplate("saml_api_login.html");
   fake_saml_idp()->SetLoginAuthHTMLTemplate("saml_api_login_auth.html");
   StartSamlAndWaitForIdpPageLoad(kFirstSAMLUserEmail);
 
   content::WindowedNotificationObserver session_start_waiter(
       chrome::NOTIFICATION_SESSION_STARTED,
       content::NotificationService::AllSources());
 
   // Fill-in the SAML IdP form and submit.
   SetSignFormField("Email", "fake_user");
@@ skipping 903 matching lines @@
 
   // Scraping one password should finish login.
   content::WindowedNotificationObserver session_start_waiter(
       chrome::NOTIFICATION_SESSION_STARTED,
       content::NotificationService::AllSources());
   ExecuteJsInSigninFrame("document.getElementById('Submit').click();");
   session_start_waiter.Wait();
 }
 
 }  // namespace chromeos