Replace gflags usages with rtc_base/flags in all targets based on test_main

webrtc/test/testsupport/test_output.cc

 /*
  *  Copyright (c) 2016 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 "webrtc/test/testsupport/test_output.h"
 
 #include <string.h>
 
-#include "gflags/gflags.h"
 #include "webrtc/rtc_base/file.h"
+#include "webrtc/rtc_base/flags.h"
 #include "webrtc/rtc_base/logging.h"
 #include "webrtc/rtc_base/pathutils.h"
 #include "webrtc/test/testsupport/fileutils.h"
 
+namespace {
+const std::string& DefaultOutputPath() {
+  static const std::string path = webrtc::test::OutputPath();
+  return path;
+}
+}
+
 DEFINE_string(test_output_dir,
-              webrtc::test::OutputPath(),
+              DefaultOutputPath().c_str(),
               "The output folder where test output should be saved.");
 
 namespace webrtc {
 namespace test {
 
 bool GetTestOutputDir(std::string* out_dir) {
-  if (FLAGS_test_output_dir.empty()) {
+  if (strlen(FLAG_test_output_dir) == 0) {
     LOG(LS_WARNING) << "No test_out_dir defined.";
     return false;
   }
-  *out_dir = FLAGS_test_output_dir;
+  *out_dir = FLAG_test_output_dir;
   return true;
 }
 
 bool WriteToTestOutput(const char* filename,
                        const uint8_t* buffer,
                        size_t length) {
-  if (FLAGS_test_output_dir.empty()) {
+  if (strlen(FLAG_test_output_dir) == 0) {
     LOG(LS_WARNING) << "No test_out_dir defined.";
     return false;
   }
 
   if (filename == nullptr || strlen(filename) == 0) {
     LOG(LS_WARNING) << "filename must be provided.";
     return false;
   }
 
   rtc::File output =
-      rtc::File::Create(rtc::Pathname(FLAGS_test_output_dir, filename));
+      rtc::File::Create(rtc::Pathname(FLAG_test_output_dir, filename));
 
   return output.IsOpen() && output.Write(buffer, length) == length;
 }
 
 bool WriteToTestOutput(const char* filename, const std::string& content) {
   return WriteToTestOutput(filename,
                            reinterpret_cast<const uint8_t*>(content.c_str()),
                            content.length());
 }
 
 }  // namespace test
 }  // namespace webrtc