Mark a couple of tests in virtual/synchronous_html_parser as flaky

No-Try: true
Tbr: Richard.Townsend@arm.com, masonfreed@chromium.org
Bug: 901056
Change-Id: Iebc85d4b4e6d0f4e57ede2b7200a9f3589c71a68
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2550106Reviewed-by: Makoto Shimazu <shimazu@chromium.org>
Commit-Queue: Makoto Shimazu <shimazu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#829477}

third_party/blink/web_tests/TestExpectations

@@ -80,6 +80,10 @@ crbug.com/901056 http/tests/devtools/modules-load-source.js [ Failure Pass ]
 crbug.com/901056 virtual/synchronous_html_parser/http/tests/inspector-protocol/issues/content-security-policy-issue-creation-img.js [ Failure Pass ]
 crbug.com/901056 virtual/synchronous_html_parser/http/tests/preload/meta-csp.html [ Failure ]
 crbug.com/901056 virtual/synchronous_html_parser/http/tests/inspector-protocol/issues/mixed-content-issue-creation-js-within-oopif.js [ Timeout ]
+
+crbug.com/901056 virtual/synchronous_html_parser/fast/css/focus-display-block-inline.html [ Failure Pass ]
+crbug.com/901056 virtual/synchronous_html_parser/fast/css/fontfaceset-multiple-families.html [ Failure Pass ]
+
 # ====== Site Isolation failures from here ======
 # See also third_party/blink/web_tests/virtual/not-site-per-process/README.md
 # Tests temporarily disabled with Site Isolation - uninvestigated bugs: