Enable content_unittests on arm64 fuchsia.fyi bot

swiftshader now supports arm64

Bug: 881334
Change-Id: I370fb7bdc361588ff69e47ac81af991ee2c02af1
Reviewed-on: https://chromium-review.googlesource.com/c/1287206Reviewed-by: Wez <wez@chromium.org>
Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Sergey Ulanov <sergeyu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600628}

testing/buildbot/chromium.fyi.json

@@ -3191,6 +3191,15 @@
         },
         "test": "base_unittests"
       },
+      {
+        "args": [
+          "--test-launcher-filter-file=../../testing/buildbot/filters/fuchsia.content_unittests.filter"
+        ],
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
+        "test": "content_unittests"
+      },
       {
         "swarming": {
           "can_use_on_swarming_builders": true

testing/buildbot/test_suite_exceptions.pyl

@@ -445,10 +445,6 @@
     },
   },
   'content_unittests': {
-    'remove_from': [
-      # chromium.fyi
-      'fuchsia-fyi-arm64-rel',  # https://crbug.com/881334
-    ],
     'modifications': {
       # chromium.memory
       'Linux ASan LSan Tests (1)': {