Disable flaky LoginPromptBrowserTest.TestCancelAuth_OnNavigation test on Linux ChromeOS

chrome/browser/ui/login/login_handler_browsertest.cc

Index: chrome/browser/ui/login/login_handler_browsertest.cc
diff --git a/chrome/browser/ui/login/login_handler_browsertest.cc b/chrome/browser/ui/login/login_handler_browsertest.cc
index ea67384bcdc88f728800bff0f4dd972e5443c7d7..c1b5e4af84e2227130b2f3c2927d6d91d7bb78b1 100644
--- a/chrome/browser/ui/login/login_handler_browsertest.cc
+++ b/chrome/browser/ui/login/login_handler_browsertest.cc
@@ -347,8 +347,15 @@ IN_PROC_BROWSER_TEST_F(LoginPromptBrowserTest, TestCancelAuth_Manual) {
   EXPECT_TRUE(observer.handlers().empty());
 }
 
+// Flaky on linux chromeos bots: crbug.com/648826.
+#if defined(OS_LINUX) && defined(OS_CHROMEOS)
+#define MAYBE_TestCancelAuth_OnNavigation DISABLED_TestCancelAuth_OnNavigation
+#else
+#define MAYBE_TestCancelAuth_OnNavigation TestCancelAuth_OnNavigation
+#endif
 // Test login prompt cancellation on navigation to a new page.
-IN_PROC_BROWSER_TEST_F(LoginPromptBrowserTest, TestCancelAuth_OnNavigation) {
+IN_PROC_BROWSER_TEST_F(LoginPromptBrowserTest,
+                       MAYBE_TestCancelAuth_OnNavigation) {
   ASSERT_TRUE(embedded_test_server()->Start());
   const GURL kAuthURL = embedded_test_server()->GetURL(kAuthBasicPage);
   const GURL kNoAuthURL = embedded_test_server()->GetURL(kNoAuthPage1);