Add realtimeanalyser-freq-data.html to MSANExpectations

BUG=703513
TBR=rtoy@chromium.org

Review-Url: https://codereview.chromium.org/2762913002 .
Cr-Commit-Position: refs/heads/master@{#458314}

third_party/WebKit/LayoutTests/MSANExpectations

@@ -43,6 +43,8 @@ crbug.com/462190 [ Linux ] inspector-protocol/heap-profiler/heap-snapshot-with-e
 crbug.com/671556 [ Linux ] virtual/mojo-loading/http/tests/security/xssAuditor/report-script-tag-replace-state.html [ Timeout Pass ]
 crbug.com/671556 [ Linux ] virtual/mojo-loading/http/tests/security/xssAuditor/report-script-tag.html [ Timeout Pass ]
 
+crbug.com/703513 [ Linux ] webaudio/Analyser/realtimeanalyser-freq-data.html [ Timeout Pass ]
+
 # Intentionally failed allocations, via partitionAllocGenericFlags()
 crbug.com/577889 [ Linux ] fast/js/typed-array-allocation-failure.html [ Crash ]