rendering.desktop/fill_shapes and balls_javascript_canvas are flaky

These test are flaky, marking them as such,
and then will investigate issue.


Bug: 1122037
Change-Id: I739c88f40c12cbaf95a777642280f9b2b645ae7c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2391502Reviewed-by: Yi Xu <yiyix@chromium.org>
Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: Juanmi Huertas <juanmihd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#804007}

tools/perf/expectations.config

@@ -200,6 +200,8 @@ crbug.com/755556 [ mac ] rendering.desktop/mix_blend_mode_animation_hue [ Skip ]
 crbug.com/1017244 [ desktop ] rendering.desktop/youtube_2018 [ Skip ]
 crbug.com/1017244 [ desktop ] rendering.desktop/youtube_pinch_2018 [ Skip ]
 crbug.com/1044962 [ win ] rendering.desktop/camera_to_webgl [ Skip ]
+crbug.com/1122037 [ mac ] rendering.desktop/fill_shapes [ Skip ]
+crbug.com/1122037 [ mac ] rendering.desktop/balls_javascript_canvas [ Skip ]
 
 # Benchmark: rendering.mobile
 crbug.com/785485 [ android-webview ] rendering.mobile/kevs_3d [ Skip ]