Disabled ExtensionApiTest.XHROnPersistentFileSystem due to flakiness.

chrome/browser/extensions/extension_fileapi_apitest.cc

Index: chrome/browser/extensions/extension_fileapi_apitest.cc
diff --git a/chrome/browser/extensions/extension_fileapi_apitest.cc b/chrome/browser/extensions/extension_fileapi_apitest.cc
index 81e10e7b0b26454dc74cae6625d730b35cdf701f..e920a9356f36521c66d13ff3083c19ea92aa861c 100644
--- a/chrome/browser/extensions/extension_fileapi_apitest.cc
+++ b/chrome/browser/extensions/extension_fileapi_apitest.cc
@@ -8,7 +8,8 @@ IN_PROC_BROWSER_TEST_F(ExtensionApiTest, DISABLED_FileAPI) {
   ASSERT_TRUE(RunExtensionTest("fileapi")) << message_;
 }
 
-IN_PROC_BROWSER_TEST_F(ExtensionApiTest, XHROnPersistentFileSystem) {
+// crbug.com/671144
+IN_PROC_BROWSER_TEST_F(ExtensionApiTest, DISABLED_XHROnPersistentFileSystem) {
   ASSERT_TRUE(RunPlatformAppTest("xhr_persistent_fs")) << message_;
 }