Revert "Use gtest_parallel with 1 worker for webrtc_perf_tests."

This reverts commit 258ed1a38ad9d4f0da798c40b6976eff2dce864f.

Reason for revert: This cl breaks the dumping of the perf proto histogram.

Original change's description:
> Use gtest_parallel with 1 worker for webrtc_perf_tests.
>
> This will enable test results to be uploaded to ResultDB.
>
> Bug: b/197492097
> Change-Id: Iec28520c4cd8f35fcff2cbd105a4b851ef41b9fc
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/239641
> Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
> Reviewed-by: Christoffer Jansson <jansson@google.com>
> Commit-Queue: Jeremy Leconte <jleconte@google.com>
> Cr-Commit-Position: refs/heads/main@{#35458}

TBR=mbonadei@webrtc.org,jansson@google.com,webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com,jleconte@webrtc.org

Change-Id: Ic4ab03d0e7f8bc1ce799d30e74420200d2f8f224
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: b/197492097
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/239644
Reviewed-by: Jeremy Leconte <jleconte@google.com>
Reviewed-by: Christoffer Jansson <jansson@google.com>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Jeremy Leconte <jleconte@google.com>
Cr-Commit-Position: refs/heads/main@{#35463}
diff --git a/tools_webrtc/mb/mb.py b/tools_webrtc/mb/mb.py
index 0c384ef..5acf31c 100755
--- a/tools_webrtc/mb/mb.py
+++ b/tools_webrtc/mb/mb.py
@@ -941,34 +941,33 @@
             else:
                 cmdline += [vpython_exe, '../../testing/test_env.py']
 
-            extra_files += [
-                '../../third_party/gtest-parallel/gtest-parallel',
-                '../../third_party/gtest-parallel/gtest_parallel.py',
-                '../../tools_webrtc/gtest-parallel-wrapper.py',
-            ]
-            sep = '\\' if self.platform == 'win32' else '/'
-            output_dir = '${ISOLATED_OUTDIR}' + sep + 'test_logs'
-            test_results = '${ISOLATED_OUTDIR}' + sep + 'gtest_output.json'
-            timeout = isolate_map[target].get('timeout', 900)
-            cmdline += [
-                '../../tools_webrtc/gtest-parallel-wrapper.py',
-                '--output_dir=%s' % output_dir,
-                '--dump_json_test_results=%s' % test_results,
-                '--gtest_color=no',
-            ]
             if test_type != 'raw':
-                # We tell gtest-parallel to interrupt the test after 900
-                # seconds, so it can exit cleanly and report results,
-                # instead of being interrupted by swarming and not
-                # reporting anything.
-                cmdline.append('--timeout=%s' % timeout)
+                extra_files += [
+                    '../../third_party/gtest-parallel/gtest-parallel',
+                    '../../third_party/gtest-parallel/gtest_parallel.py',
+                    '../../tools_webrtc/gtest-parallel-wrapper.py',
+                ]
+                sep = '\\' if self.platform == 'win32' else '/'
+                output_dir = '${ISOLATED_OUTDIR}' + sep + 'test_logs'
+                test_results = '${ISOLATED_OUTDIR}' + sep + 'gtest_output.json'
+                timeout = isolate_map[target].get('timeout', 900)
+                cmdline += [
+                    '../../tools_webrtc/gtest-parallel-wrapper.py',
+                    '--output_dir=%s' % output_dir,
+                    '--dump_json_test_results=%s' % test_results,
+                    '--gtest_color=no',
+                    # We tell gtest-parallel to interrupt the test after 900
+                    # seconds, so it can exit cleanly and report results,
+                    # instead of being interrupted by swarming and not
+                    # reporting anything.
+                    '--timeout=%s' % timeout,
+                ]
+                if test_type == 'non_parallel_console_test_launcher':
+                    # Still use the gtest-parallel-wrapper.py script since we
+                    # need it to run tests on swarming, but don't execute tests
+                    # in parallel.
+                    cmdline.append('--workers=1')
                 must_retry = True
-            if (test_type == 'raw' or
-                    test_type == 'non_parallel_console_test_launcher'):
-                # Still use the gtest-parallel-wrapper.py script since we
-                # need it to run tests on swarming, but don't execute tests
-                # in parallel.
-                cmdline.append('--workers=1')
 
             asan = 'is_asan=true' in vals['gn_args']
             lsan = 'is_lsan=true' in vals['gn_args']
diff --git a/tools_webrtc/mb/mb_unittest.py b/tools_webrtc/mb/mb_unittest.py
index 125850d..0cc2a4d 100755
--- a/tools_webrtc/mb/mb_unittest.py
+++ b/tools_webrtc/mb/mb_unittest.py
@@ -489,10 +489,7 @@
     self.assertEqual(files, [
         '../../.vpython',
         '../../testing/test_env.py',
-        '../../third_party/gtest-parallel/gtest-parallel',
-        '../../third_party/gtest-parallel/gtest_parallel.py',
         '../../tools_webrtc/flags_compatibility.py',
-        '../../tools_webrtc/gtest-parallel-wrapper.py',
         'base_unittests',
     ])
     self.assertEqual(command, [
@@ -500,11 +497,6 @@
         '../../tools_webrtc/flags_compatibility.py',
         'vpython',
         '../../testing/test_env.py',
-        '../../tools_webrtc/gtest-parallel-wrapper.py',
-        '--output_dir=${ISOLATED_OUTDIR}/test_logs',
-        '--dump_json_test_results=${ISOLATED_OUTDIR}/gtest_output.json',
-        '--gtest_color=no',
-        '--workers=1',
         './base_unittests',
         '--asan=0',
         '--lsan=0',