Trace Report UI

This webui implements chrome://traces, which shows trace reports collected by background tracing. To test, simply navigating to the URL might be sufficient if traces are present. If no traces, chrome can be started with a trace config to force trace collection:

1. Create a new config.pbtxt file anywhere on your desktop. Copy the config below and save the file.

scenarios: {
  scenario_name: "Test"
  trace_config: {
    data_sources: {
      config: {
        name: "org.chromium.trace_event"
        track_event_config: {
          disabled_categories: ["*"],
          enabled_categories: ["toplevel", "__metadata"]
        },
      }
    }
    data_sources: { config: { name: "org.chromium.trace_metadata" } }
  }
  start_rules: {
    name: "Timer Start"
    delay_ms: 0
  }
  upload_rules: {
    name: "Timer End"
    delay_ms: 5000
  }
}

2. Then compile the proto with:

<outdir>/protoc --encode=perfetto.protos.ChromeFieldTracingConfig \
--proto_path=third_party/perfetto third_party/perfetto/protos/perfetto/config/\
chrome/scenario_config.proto < config.pbtxt > config.pb

config.pbtxt is the absolute path where your file is on your desktop. Keep the < > around config.pbtxt from the command above.

3. And run chrome with command line:

--enable-background-tracing=config.pb

You should be able to now collect trace reports on your computer and preview them on chrome://traces.