Reland "[tbmv3] Add an integration test for run_tbmv3_metric"

This is a reland of c401a7d6, which
should be fine to land now that we have merged
https://chromium-review.googlesource.com/c/chromium/src/+/2089827

Original change's description:
> [tbmv3] Add an integration test for run_tbmv3_metric
>
> Adding a simple smoke test to make sure run_tbmv3_metric does not break
> silently.
>
> Change-Id: I54f4d525e221eef403678034efde505ee19cbc1e
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2078736
> Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
> Reviewed-by: Deep Roy <dproy@chromium.org>
> Reviewed-by: Mikhail Khokhlov <khokhlov@google.com>
> Commit-Queue: Deep Roy <dproy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#747385}

Change-Id: I6fbaa19940658ad17ec805c0b29cca7dd5d9690c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2091588Reviewed-by: Mikhail Khokhlov <khokhlov@google.com>
Commit-Queue: Deep Roy <dproy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#748456}

tools/perf/core/perfetto_binary_roller/binary_deps_manager_unittest.py

@@ -17,9 +17,11 @@ class BinaryDepsManagerTests(unittest.TestCase):
   def setUp(self):
     self.temp_dir = tempfile.mkdtemp()
     self.config_path = os.path.join(self.temp_dir, 'config.json')
+    self.original_config_path = binary_deps_manager.CONFIG_PATH
     binary_deps_manager.CONFIG_PATH = self.config_path
 
   def tearDown(self):
+    binary_deps_manager.CONFIG_PATH = self.original_config_path
     shutil.rmtree(self.temp_dir)
 
   def writeConfig(self, config):

tools/perf/core/tbmv3/run_tbmv3_metric.py

@@ -24,18 +24,16 @@ from core.tbmv3 import trace_processor
 
 _CHROMIUM_SRC_PATH  = os.path.join(
     os.path.dirname(__file__), '..', '..', '..', '..')
-_DEFAULT_TP_PATH = os.path.realpath(os.path.join(
-    _CHROMIUM_SRC_PATH, 'out', 'Debug', 'trace_processor_shell'))
-
 
 
 def _WriteHistogramSetToFile(histograms, outfile):
   with open(outfile, 'w') as f:
     json.dump(histograms.AsDicts(), f, indent=2, sort_keys=True,
               separators=(',', ': '))
+    f.write("\n")
 
 
-def Main():
+def Main(cli_args):
   parser = argparse.ArgumentParser(
     description='[Experimental] Runs TBMv3 metrics on local traces and '
     'produces histogram json.')
@@ -43,12 +41,13 @@ def Main():
                       help='Trace file you want to compute metric on')
   parser.add_argument('--metric', required=True,
                       help=('Name of the metric you want to run'))
-  parser.add_argument('--trace-processor-path', default=_DEFAULT_TP_PATH,
-                      help='Path to trace processor shell. '
-                      'Default: %(default)s')
+  parser.add_argument(
+      '--trace-processor-path',
+      help='Path to trace processor shell. '
+      'Default: Binary downloaded from cloud storage.')
   parser.add_argument('--outfile', default='results.json',
                       help='Path to output file. Default: %(default)s')
-  args = parser.parse_args()
+  args = parser.parse_args(cli_args)
 
   histograms = trace_processor.RunMetric(args.trace_processor_path,
                                          args.trace, args.metric)
@@ -57,4 +56,4 @@ def Main():
 
 
 if __name__ == '__main__':
-  sys.exit(Main())
+  sys.exit(Main(sys.argv[1:]))

tools/perf/core/tbmv3/run_tbmv3_metric_unittest.py

+# Copyright 2020 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+"""Integration tests for run_tbmv3_metric.py.
+
+These test check run_tbmv3_metric works end to end, using the real trace
+processor shell.
+"""
+
+import json
+import os
+import shutil
+import tempfile
+import unittest
+
+from core.tbmv3 import run_tbmv3_metric
+
+from tracing.value import histogram_set
+
+# For testing the TBMv3 workflow we use dummy_metric defined in
+# tools/perf/core/tbmv3/metrics/dummy_metric_*.
+# This metric ignores the trace data and outputs a histogram with
+# the following name and unit:
+DUMMY_HISTOGRAM_NAME = 'dummy::simple_field'
+DUMMY_HISTOGRAM_UNIT = 'count_smallerIsBetter'
+
+
+class RunTbmv3MetricIntegrationTests(unittest.TestCase):
+  def setUp(self):
+    self.output_dir = tempfile.mkdtemp()
+    self.trace_path = self.CreateEmptyProtoTrace()
+    self.outfile_path = os.path.join(self.output_dir, 'out.json')
+
+  def tearDown(self):
+    shutil.rmtree(self.output_dir)
+
+  def CreateEmptyProtoTrace(self):
+    """Create an empty file as a proto trace."""
+    with tempfile.NamedTemporaryFile(
+        dir=self.output_dir, delete=False) as trace_file:
+      # Open temp file and close it so it's written to disk.
+      pass
+    return trace_file.name
+
+  def testRunTbmv3MetricOnDummyMetric(self):
+    run_tbmv3_metric.Main([
+        '--trace', self.trace_path,
+        '--metric', 'dummy_metric',
+        '--outfile', self.outfile_path,
+    ])
+
+    with open(self.outfile_path) as f:
+      results = json.load(f)
+
+    out_histograms = histogram_set.HistogramSet()
+    out_histograms.ImportDicts(results)
+
+    hist = out_histograms.GetHistogramNamed(DUMMY_HISTOGRAM_NAME)
+    self.assertEqual(hist.unit, DUMMY_HISTOGRAM_UNIT)
+    self.assertEqual(hist.num_values, 1)
+    self.assertEqual(hist.average, 42)