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

webrtc/voice_engine/BUILD.gn

 # Copyright (c) 2014 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.
 
 import("../webrtc.gni")
 
@@ skipping 182 matching lines @@
       "../modules/utility",
       "../modules/video_capture:video_capture",
       "../rtc_base:rtc_base_approved",
       "../rtc_base:rtc_base_tests_utils",
       "../system_wrappers",
       "../test:test_common",
       "../test:test_main",
       "../test:video_test_common",
       "//testing/gmock",
       "//testing/gtest",
-      "//third_party/gflags",
     ]
 
     if (is_android) {
       deps += [ "//testing/android/native_test:native_test_native_code" ]
       shard_timeout = 900
     }
 
     sources = [
       "channel_unittest.cc",
       "file_player_unittests.cc",
@@ skipping 92 matching lines @@
         ]
       }
 
       if (!build_with_chromium && is_clang) {
         # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
         suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
       }
     }
   }
 }