[Sheriff] Mark two tests as failing on disable-layout-ng

TBR=robertma@chromium.org

Bug: 1151784
Change-Id: I7d93332e8217aa71867f84874cd06aa5d0ad8037
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2554290Reviewed-by: Stephen McGruer <smcgruer@chromium.org>
Commit-Queue: Stephen McGruer <smcgruer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#830080}

third_party/blink/web_tests/FlagExpectations/disable-layout-ng

@@ -221,6 +221,8 @@ crbug.com/591099 external/wpt/css/css-text/white-space/control-chars-00C.html [
 crbug.com/591099 external/wpt/css/css-text/white-space/line-edge-white-space-collapse-001.html [ Failure ]
 crbug.com/591099 external/wpt/css/css-text/white-space/line-edge-white-space-collapse-002.html [ Failure ]
 crbug.com/591099 external/wpt/css/css-text/white-space/pre-line-with-space-and-newline.html [ Failure ]
+crbug.com/1151784 external/wpt/css/css-text/white-space/seg-break-transformation-016.tentative.html [ Failure ]
+crbug.com/1151784 external/wpt/css/css-text/white-space/seg-break-transformation-017.tentative.html [ Failure ]
 
 ### external/wpt/css/css-text/word-break/
 crbug.com/591099 external/wpt/css/css-text/word-break/word-break-break-all-004.html [ Failure ]