Add test expectations for recent regressions caught by Site Isolation FYI bot.

third_party/WebKit/LayoutTests/FlagExpectations/site-per-process

Index: third_party/WebKit/LayoutTests/FlagExpectations/site-per-process
diff --git a/third_party/WebKit/LayoutTests/FlagExpectations/site-per-process b/third_party/WebKit/LayoutTests/FlagExpectations/site-per-process
index 42b4d5cdbd3ae0a9ebd7d673018a3ebe637d677e..ddad0d04e2b22a4417fbdbb4bcf1055d05bb3289 100644
--- a/third_party/WebKit/LayoutTests/FlagExpectations/site-per-process
+++ b/third_party/WebKit/LayoutTests/FlagExpectations/site-per-process
@@ -80,6 +80,14 @@ http/tests/navigation/success200-frames-loadsame.html [ Failure ]
 http/tests/xmlhttprequest/origin-whitelisting-all.html [ Failure ]
 http/tests/xmlhttprequest/origin-whitelisting-ip-addresses.html [ Failure ]
 
+# https://crbug.com/601584 - No OOPIF support for UserGestureIndicator triggers
+#                            cross-origin-iframe.html layout test failure
+http/tests/bluetooth/https/requestDevice/cross-origin-iframe.html [ Failure ]
+
+# https://crbug.com/601581 - m_persistedPluginWidget->isFrameView() assert
+#                            fails in --site-per-process mode
+http/tests/security/xss-DENIED-object-element.html [ Crash ]
+
 # TODO(alexmos,lukasza): Triage these failures and assign more specific bugs.
 
 # No repro (maybe flaky? maybe really fixed? maybe repros only in debug build?):