Move common test flags to a separate library.

This enables the possibility to use these flags from other main
functions.

Bug: b/217701950, b/238157120
Change-Id: I6e9f09c4be39b2ac690c8e6b6da380ef3c81f460
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/269140
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37582}

test/BUILD.gn

@@ -485,6 +485,16 @@ if (rtc_include_tests && !build_with_chromium) {
     absl_deps = [ "//third_party/abseil-cpp/absl/flags:flag" ]
   }
 
+  rtc_library("test_flags") {
+    visibility = [ "*" ]
+    testonly = true
+    sources = [
+      "test_flags.cc",
+      "test_flags.h",
+    ]
+    absl_deps = [ "//third_party/abseil-cpp/absl/flags:flag" ]
+  }
+
   rtc_library("test_main_lib") {
     visibility = [ "*" ]
     testonly = true
@@ -497,6 +507,7 @@ if (rtc_include_tests && !build_with_chromium) {
       ":field_trial",
       ":perf_test",
       ":resources_dir_flag",
+      ":test_flags",
       ":test_support",
       "../rtc_base",
       "../rtc_base:checks",

test/test_flags.cc

@@ -0,0 +1,38 @@
+/*
+ *  Copyright (c) 2022 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "test/test_flags.h"
+
+#include <string>
+#include <vector>
+
+#include "absl/flags/flag.h"
+
+ABSL_FLAG(std::string,
+          force_fieldtrials,
+          "",
+          "Field trials control experimental feature code which can be forced. "
+          "E.g. running with --force_fieldtrials=WebRTC-FooFeature/Enable/"
+          " will assign the group Enable to field trial WebRTC-FooFeature.");
+
+ABSL_FLAG(std::vector<std::string>,
+          plot,
+          {},
+          "List of metrics that should be exported for plotting (if they are "
+          "available). Example: psnr,ssim,encode_time. To plot all available "
+          " metrics pass 'all' as flag value");
+
+ABSL_FLAG(
+    std::string,
+    isolated_script_test_perf_output,
+    "",
+    "Path where the perf results should be stored in proto format described "
+    "described by histogram.proto in "
+    "https://chromium.googlesource.com/catapult/.");

test/test_flags.h

@@ -0,0 +1,22 @@
+/*
+ *  Copyright (c) 2022 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#ifndef TEST_TEST_FLAGS_H_
+#define TEST_TEST_FLAGS_H_
+
+#include <string>
+#include <vector>
+
+#include "absl/flags/declare.h"
+
+ABSL_DECLARE_FLAG(std::string, force_fieldtrials);
+ABSL_DECLARE_FLAG(std::vector<std::string>, plot);
+ABSL_DECLARE_FLAG(std::string, isolated_script_test_perf_output);
+
+#endif  // TEST_TEST_FLAGS_H_

test/test_main_lib.cc

@@ -28,6 +28,7 @@
 #include "system_wrappers/include/metrics.h"
 #include "test/field_trial.h"
 #include "test/gtest.h"
+#include "test/test_flags.h"
 #include "test/testsupport/perf_test.h"
 #include "test/testsupport/resources_dir_flag.h"
 
@@ -64,22 +65,6 @@ ABSL_FLAG(std::string,
           "",
           "Path to output an empty JSON file which Chromium infra requires.");
 
-ABSL_FLAG(
-    std::string,
-    isolated_script_test_perf_output,
-    "",
-    "Path where the perf results should be stored in proto format described "
-    "described by histogram.proto in "
-    "https://chromium.googlesource.com/catapult/.");
-
-constexpr char kPlotAllMetrics[] = "all";
-ABSL_FLAG(std::vector<std::string>,
-          plot,
-          {},
-          "List of metrics that should be exported for plotting (if they are "
-          "available). Example: psnr,ssim,encode_time. To plot all available "
-          " metrics pass 'all' as flag value");
-
 ABSL_FLAG(bool, logs, true, "print logs to stderr");
 ABSL_FLAG(bool, verbose, false, "verbose logs to stderr");
 
@@ -89,17 +74,12 @@ ABSL_FLAG(std::string,
           "Path to collect trace events (json file) for chrome://tracing. "
           "If not set, events aren't captured.");
 
-ABSL_FLAG(std::string,
-          force_fieldtrials,
-          "",
-          "Field trials control experimental feature code which can be forced. "
-          "E.g. running with --force_fieldtrials=WebRTC-FooFeature/Enable/"
-          " will assign the group Enable to field trial WebRTC-FooFeature.");
-
 namespace webrtc {
 
 namespace {
 
+constexpr char kPlotAllMetrics[] = "all";
+
 class TestMainImpl : public TestMain {
  public:
   int Init(int* argc, char* argv[]) override { return Init(); }