Disable flaky test ExecuteDefaultTaskOnDrive/FileManagerBrowserTest

chrome/browser/chromeos/file_manager/file_manager_browsertest.cc

Index: chrome/browser/chromeos/file_manager/file_manager_browsertest.cc
diff --git a/chrome/browser/chromeos/file_manager/file_manager_browsertest.cc b/chrome/browser/chromeos/file_manager/file_manager_browsertest.cc
index 31d00e9d64da9c769f6a215206b584779395b59d..e8e378db623a39ee8803fa376b10ae9ea4728785 100644
--- a/chrome/browser/chromeos/file_manager/file_manager_browsertest.cc
+++ b/chrome/browser/chromeos/file_manager/file_manager_browsertest.cc
@@ -366,8 +366,9 @@ WRAPPED_INSTANTIATE_TEST_CASE_P(
 #else
 #define MAYBE_ExecuteDefaultTaskOnDrive ExecuteDefaultTaskOnDrive
 #endif
+// Flaky: crbug.com/699978
 WRAPPED_INSTANTIATE_TEST_CASE_P(
-    MAYBE_ExecuteDefaultTaskOnDrive,
+    DISABLED_ExecuteDefaultTaskOnDrive,
     FileManagerBrowserTest,
     ::testing::Values(TestParameter(NOT_IN_GUEST_MODE,
                                     "executeDefaultTaskOnDrive")));