Add textproto output for trace summaries

In addition to binary protobuf, also export the more human friendly
.textproto format of the trace summary.

Additionally fix the naming of the binary trace summary file to be
'.pb'.

Change-Id: I3b68abffbca45e2ab95e8ae602d0f8c548d9f08b
Reviewed-on: https://chromium-review.googlesource.com/c/crossbench/+/6666724
Reviewed-by: Charles Dick <[email protected]>
Commit-Queue: Kameron Lutes <[email protected]>

Author: kalutes

crossbench/probes/perfetto/trace_processor/trace_processor.py

@@ -11,6 +11,7 @@
 from typing import TYPE_CHECKING, Iterable, Optional, Self, Type
 
 import pandas as pd
+from google.protobuf import text_format
 from google.protobuf.json_format import MessageToJson
 from perfetto.batch_trace_processor.api import (BatchTraceProcessor,
                                                 BatchTraceProcessorConfig)
@@ -461,12 +462,13 @@ def _summarize_trace(self, tp: TraceProcessor) -> ProbeResult:
       proto_result = tp.trace_summary(
           specs=list(self.probe.metric_definitions), metric_ids=metric_ids)
 
-      proto_file = self.local_result_path / "v2_metrics.proto"
+      proto_file = self.local_result_path / "v2_metrics.pb"
+      proto_file.write_bytes(proto_result.SerializeToString())
 
-      with proto_file.open("wb") as f:
-        f.write(proto_result.SerializeToString())
+      textproto_file = self.local_result_path / "v2_metrics.textproto"
+      textproto_file.write_bytes(text_format.MessageToBytes(proto_result))
 
-      return LocalProbeResult(file=[proto_file])
+      return LocalProbeResult(file=[proto_file, textproto_file])
 
 
   @property