Auto merge of #19207 - asajeffrey:test-perf-add-base-url-option, r=edunham

Add --base option to test-perf.

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Add a `--base <URL>` option to test-perf, which is handy for two reasons: a) it reduces randomness in tests by allowing tests to be file URLs, and b) it doesn't require running the test suite as root (the tp5n manifest hardwires tests served from port 80 on localhost).

---
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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes do not require tests because this is test infrastructure

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etc/ci/performance/test_perf.sh

@@ -35,13 +35,4 @@ mkdir -p servo
 mkdir -p output # Test result will be saved to output/perf-<timestamp>.json
 ./git_log_to_json.sh > servo/revision.json
 
-if [[ "${#}" -eq 1 ]]; then
-  if [[ "${1}" = "--submit" ]]; then
-    ./test_all.sh --servo --submit
-  else
-    echo "Unrecognized argument: ${1}; Ignore and proceed without submitting"
-    ./test_all.sh --servo
-  fi
-else
-  ./test_all.sh --servo
-fi
+./test_all.sh --servo ${*}