speedscope fails to open Catapult files that don't all specify a pid

We only use pid for the name of the profie.
None of our fields afterwards use it, and simply refer to a tid. This is to keep the json size down.

speedscope rejects these perfectly valid files. I'd like to move off Perfetto and over to speedscope. But I forget what issues that I had using it in the past. These files open fine in Perfetto.

Also when speedscope fails to parse these files, it produces no output in the console to help identify what went wrong or what line failed.

```
{
"displayTimeUnit": "ms",
"systemTraceEvents": "SystemTraceData",
"traceEvents": [

{
"name": "process_name",
"ph": "M",
"pid": 0,
"args": {
"name": "SkyPools.json"
}
},

{
"name": "thread_name",
"ph": "M",
"tid": 0,
"args": {
"name": "T0 b0 2"
}
},

{
"name": "TT-UiMapAtlas5",
"ph": "X",
"ts": 0,
"dur": 5593344,
"tid": 0,
"cat": "TT"
},

]
}
```