Disable allow_csp_from-header.html on Site Isolation bots

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 fe732fa2521e0e29e06e687b8f728ca5469ef462..83ea7fbcee62f5ae5d701988301610afdd1ed027 100644
--- a/third_party/WebKit/LayoutTests/FlagExpectations/site-per-process
+++ b/third_party/WebKit/LayoutTests/FlagExpectations/site-per-process
@@ -95,6 +95,9 @@ crbug.com/623265 http/tests/inspector/indexeddb/resources-panel.html [ Timeout ]
 # layout_test_runtime_flags_.have_top_loading_frame()
 crbug.com/645641 imported/wpt/html/syntax/parsing/html5lib_tests19.html [ Crash Failure ]
 
+# https://crbug.com/657081 - Allow-CSP-From header test (experimental feature)
+crbug.com/657081 http/tests/security/contentSecurityPolicy/embeddedEnforcement/allow_csp_from-header.html [ Failure ]
+
 # TODO(lukasza, alexmos): Triage these failures.
 Bug(none) fast/frames/cached-frame-counter.html [ Timeout ]
 Bug(none) fast/frames/frame-limit.html [ Timeout ]