Unblock wpt import by adding flaky expectations for some tests

Bug: 1049607
Change-Id: Id99fb07fc85539dad0d4928761e1abe2857541fe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2042371
Auto-Submit: Luke Z <lpz@chromium.org>
Commit-Queue: Robert Ma <robertma@chromium.org>
Reviewed-by: Robert Ma <robertma@chromium.org>
Cr-Commit-Position: refs/heads/master@{#739041}

third_party/blink/web_tests/TestExpectations

@@ -6641,3 +6641,9 @@ crbug.com/1048149 [ Mac ] virtual/form-controls-refresh-disabled/fast/forms/cale
 # Upcoming DevTools change
 crbug.com/1006759 http/tests/devtools/profiler/cpu-profiler-save-load.js [ Pass Failure ]
 crbug.com/1006759 http/tests/devtools/profiler/heap-snapshot-loader.js [ Pass Failure ]
+
+# Flaky tests blocking WPT import
+crbug.com/1049607 external/wpt/fetch/api/response/response-error-from-stream.html [ Pass Failure ]
+crbug.com/1049607 virtual/omt-worker-fetch/external/wpt/fetch/api/response/response-error-from-stream.html [ Pass Failure ]
+crbug.com/1049607 [ Linux ] external/wpt/js-self-profiling/idlharness.any.html [ Pass Failure ]
+crbug.com/1049607 [ Linux ] external/wpt/js-self-profiling/idlharness.any.worker.html [ Pass Failure ]