diff --git a/BUILD.gn b/BUILD.gn
index 19a60d5..6641e2f 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -6,16 +6,549 @@
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
-import("webrtc/webrtc.gni")
+import("//build/config/linux/pkg_config.gni")
+import("//build/config/sanitizers/sanitizers.gni")
+import("webrtc.gni")
+import("//third_party/protobuf/proto_library.gni")
+if (is_android) {
+  import("//build/config/android/config.gni")
+  import("//build/config/android/rules.gni")
+}
 
-group("default") {
-  testonly = true
-  deps = [
-    "//webrtc",
-    "//webrtc/examples",
-    "//webrtc/rtc_tools",
-  ]
+if (!build_with_chromium) {
+  group("default") {
+    testonly = true
+    deps = [
+      ":webrtc",
+      "examples",
+      "rtc_tools",
+    ]
+    if (rtc_include_tests) {
+      deps += [ ":webrtc_tests" ]
+    }
+  }
+}
+
+# Contains the defines and includes in common.gypi that are duplicated both as
+# target_defaults and direct_dependent_settings.
+config("common_inherited_config") {
+  defines = []
+  cflags = []
+  ldflags = []
+  if (build_with_mozilla) {
+    defines += [ "WEBRTC_MOZILLA_BUILD" ]
+  }
+
+  # Some tests need to declare their own trace event handlers. If this define is
+  # not set, the first time TRACE_EVENT_* is called it will store the return
+  # value for the current handler in an static variable, so that subsequent
+  # changes to the handler for that TRACE_EVENT_* will be ignored.
+  # So when tests are included, we set this define, making it possible to use
+  # different event handlers in different tests.
   if (rtc_include_tests) {
-    deps += [ "//webrtc:webrtc_tests" ]
+    defines += [ "WEBRTC_NON_STATIC_TRACE_EVENT_HANDLERS=1" ]
+  } else {
+    defines += [ "WEBRTC_NON_STATIC_TRACE_EVENT_HANDLERS=0" ]
+  }
+  if (build_with_chromium) {
+    defines += [
+      # TODO(kjellander): Cleanup unused ones and move defines closer to
+      # the source when webrtc:4256 is completed.
+      "FEATURE_ENABLE_VOICEMAIL",
+      "GTEST_RELATIVE_PATH",
+      "WEBRTC_CHROMIUM_BUILD",
+    ]
+    include_dirs = [
+      # The overrides must be included first as that is the mechanism for
+      # selecting the override headers in Chromium.
+      "../webrtc_overrides",
+
+      # Allow includes to be prefixed with webrtc/ in case it is not an
+      # immediate subdirectory of the top-level.
+      ".",
+    ]
+  }
+  if (is_posix) {
+    defines += [ "WEBRTC_POSIX" ]
+  }
+  if (is_ios) {
+    defines += [
+      "WEBRTC_MAC",
+      "WEBRTC_IOS",
+    ]
+  }
+  if (is_linux) {
+    defines += [ "WEBRTC_LINUX" ]
+  }
+  if (is_mac) {
+    defines += [ "WEBRTC_MAC" ]
+  }
+  if (is_win) {
+    defines += [
+      "WEBRTC_WIN",
+      "_CRT_SECURE_NO_WARNINGS",  # Suppress warnings about _vsnprinf
+    ]
+  }
+  if (is_android) {
+    defines += [
+      "WEBRTC_LINUX",
+      "WEBRTC_ANDROID",
+    ]
+  }
+  if (is_chromeos) {
+    defines += [ "CHROMEOS" ]
+  }
+
+  if (rtc_sanitize_coverage != "") {
+    assert(is_clang, "sanitizer coverage requires clang")
+    cflags += [ "-fsanitize-coverage=${rtc_sanitize_coverage}" ]
+    ldflags += [ "-fsanitize-coverage=${rtc_sanitize_coverage}" ]
+  }
+
+  if (is_ubsan) {
+    cflags += [ "-fsanitize=float-cast-overflow" ]
+  }
+
+  # TODO(GYP): Support these in GN.
+  # if (is_bsd) {
+  #   defines += [ "BSD" ]
+  # }
+  # if (is_openbsd) {
+  #   defines += [ "OPENBSD" ]
+  # }
+  # if (is_freebsd) {
+  #   defines += [ "FREEBSD" ]
+  # }
+}
+
+config("common_config") {
+  cflags = []
+  cflags_cc = []
+  defines = []
+
+  if (rtc_enable_protobuf) {
+    defines += [ "WEBRTC_ENABLE_PROTOBUF=1" ]
+  } else {
+    defines += [ "WEBRTC_ENABLE_PROTOBUF=0" ]
+  }
+
+  if (rtc_restrict_logging) {
+    defines += [ "WEBRTC_RESTRICT_LOGGING" ]
+  }
+
+  if (rtc_include_internal_audio_device) {
+    defines += [ "WEBRTC_INCLUDE_INTERNAL_AUDIO_DEVICE" ]
+  }
+
+  if (!rtc_libvpx_build_vp9) {
+    defines += [ "RTC_DISABLE_VP9" ]
+  }
+
+  if (rtc_enable_sctp) {
+    defines += [ "HAVE_SCTP" ]
+  }
+
+  if (rtc_enable_external_auth) {
+    defines += [ "ENABLE_EXTERNAL_AUTH" ]
+  }
+
+  if (build_with_chromium) {
+    defines += [
+      # NOTICE: Since common_inherited_config is used in public_configs for our
+      # targets, there's no point including the defines in that config here.
+      # TODO(kjellander): Cleanup unused ones and move defines closer to the
+      # source when webrtc:4256 is completed.
+      "HAVE_WEBRTC_VIDEO",
+      "HAVE_WEBRTC_VOICE",
+      "LOGGING_INSIDE_WEBRTC",
+      "USE_WEBRTC_DEV_BRANCH",
+    ]
+  } else {
+    if (is_posix) {
+      # Enable more warnings: -Wextra is currently disabled in Chromium.
+      cflags = [
+        "-Wextra",
+
+        # Repeat some flags that get overridden by -Wextra.
+        "-Wno-unused-parameter",
+        "-Wno-missing-field-initializers",
+        "-Wno-strict-overflow",
+      ]
+      cflags_cc = [
+        "-Wnon-virtual-dtor",
+
+        # This is enabled for clang; enable for gcc as well.
+        "-Woverloaded-virtual",
+      ]
+    }
+
+    if (is_clang) {
+      cflags += [
+        "-Wc++11-narrowing",
+        "-Wimplicit-fallthrough",
+        "-Wthread-safety",
+        "-Winconsistent-missing-override",
+        "-Wundef",
+      ]
+
+      # use_xcode_clang only refers to the iOS toolchain, host binaries use
+      # chromium's clang always.
+      if (!is_nacl &&
+          (!use_xcode_clang || current_toolchain == host_toolchain)) {
+        # Flags NaCl (Clang 3.7) and Xcode 7.3 (Clang clang-703.0.31) do not
+        # recognize.
+        cflags += [ "-Wunused-lambda-capture" ]
+      }
+    }
+  }
+
+  if (current_cpu == "arm64") {
+    defines += [ "WEBRTC_ARCH_ARM64" ]
+    defines += [ "WEBRTC_HAS_NEON" ]
+  }
+
+  if (current_cpu == "arm") {
+    defines += [ "WEBRTC_ARCH_ARM" ]
+    if (arm_version >= 7) {
+      defines += [ "WEBRTC_ARCH_ARM_V7" ]
+      if (arm_use_neon) {
+        defines += [ "WEBRTC_HAS_NEON" ]
+      }
+    }
+  }
+
+  if (current_cpu == "mipsel") {
+    defines += [ "MIPS32_LE" ]
+    if (mips_float_abi == "hard") {
+      defines += [ "MIPS_FPU_LE" ]
+    }
+    if (mips_arch_variant == "r2") {
+      defines += [ "MIPS32_R2_LE" ]
+    }
+    if (mips_dsp_rev == 1) {
+      defines += [ "MIPS_DSP_R1_LE" ]
+    } else if (mips_dsp_rev == 2) {
+      defines += [
+        "MIPS_DSP_R1_LE",
+        "MIPS_DSP_R2_LE",
+      ]
+    }
+  }
+
+  if (is_android && !is_clang) {
+    # The Android NDK doesn"t provide optimized versions of these
+    # functions. Ensure they are disabled for all compilers.
+    cflags += [
+      "-fno-builtin-cos",
+      "-fno-builtin-sin",
+      "-fno-builtin-cosf",
+      "-fno-builtin-sinf",
+    ]
+  }
+
+  if (use_libfuzzer || use_drfuzz || use_afl) {
+    # Used in Chromium's overrides to disable logging
+    defines += [ "WEBRTC_UNSAFE_FUZZER_MODE" ]
+  }
+}
+
+config("common_objc") {
+  libs = [ "Foundation.framework" ]
+}
+
+if (!build_with_chromium) {
+  # Target to build all the WebRTC production code.
+  rtc_static_library("webrtc") {
+    # Only the root target should depend on this.
+    visibility = [ "//:default" ]
+
+    sources = []
+    complete_static_lib = true
+    defines = []
+
+    deps = [
+      ":webrtc_common",
+      "api",
+      "api:transport_api",
+      "audio",
+      "call",
+      "common_audio",
+      "common_video",
+      "logging",
+      "media",
+      "modules",
+      "modules/video_capture:video_capture_internal_impl",
+      "ortc",
+      "p2p",
+      "pc",
+      "rtc_base",
+      "sdk",
+      "stats",
+      "system_wrappers:system_wrappers_default",
+      "video",
+      "voice_engine",
+    ]
+
+    if (rtc_enable_protobuf) {
+      defines += [ "ENABLE_RTC_EVENT_LOG" ]
+      deps += [ "logging:rtc_event_log_proto" ]
+    }
+  }
+
+  if (rtc_include_tests) {
+    # Target to build all the WebRTC tests (but not examples or tools).
+    # Executable in order to get a target that links all WebRTC code.
+    rtc_executable("webrtc_tests") {
+      testonly = true
+
+      # Only the root target should depend on this.
+      visibility = [ "//:default" ]
+
+      deps = [
+        ":rtc_unittests",
+        ":video_engine_tests",
+        ":webrtc_nonparallel_tests",
+        ":webrtc_perf_tests",
+        "common_audio:common_audio_unittests",
+        "common_video:common_video_unittests",
+        "media:rtc_media_unittests",
+        "modules:modules_tests",
+        "modules:modules_unittests",
+        "modules/audio_coding:audio_coding_tests",
+        "modules/audio_processing:audio_processing_tests",
+        "modules/remote_bitrate_estimator:bwe_simulations_tests",
+        "modules/rtp_rtcp:test_packet_masks_metrics",
+        "modules/video_capture:video_capture_internal_impl",
+        "ortc:ortc_unittests",
+        "pc:peerconnection_unittests",
+        "pc:rtc_pc_unittests",
+        "rtc_base:rtc_base_tests_utils",
+        "stats:rtc_stats_unittests",
+        "system_wrappers:system_wrappers_unittests",
+        "test",
+        "video:screenshare_loopback",
+        "video:video_loopback",
+        "voice_engine:voice_engine_unittests",
+      ]
+      if (is_android) {
+        deps += [
+          ":android_junit_tests",
+          "sdk/android:libjingle_peerconnection_android_unittest",
+        ]
+      } else {
+        deps += [ "modules/video_capture:video_capture_tests" ]
+      }
+      if (!is_ios) {
+        deps += [ "voice_engine:voe_auto_test" ]
+      }
+      if (rtc_enable_protobuf) {
+        deps += [
+          "audio:low_bandwidth_audio_test",
+          "logging:rtc_event_log2rtp_dump",
+        ]
+      }
+    }
+  }
+}
+
+rtc_static_library("webrtc_common") {
+  # TODO(mbonadei): Remove (bugs.webrtc.org/7745)
+  # Enabling GN check triggers cyclic dependency error:
+  # :webrtc_common ->
+  # api:video_frame_api ->
+  # system_wrappers:system_wrappers ->
+  # webrtc_common
+  check_includes = false
+  sources = [
+    "common_types.cc",
+    "common_types.h",
+    "typedefs.h",
+  ]
+
+  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" ]
+  }
+}
+
+if (use_libfuzzer || use_drfuzz || use_afl) {
+  # This target is only here for gn to discover fuzzer build targets under
+  # webrtc/test/fuzzers/.
+  group("webrtc_fuzzers_dummy") {
+    testonly = true
+    deps = [
+      "test/fuzzers:webrtc_fuzzer_main",
+    ]
+  }
+}
+
+if (rtc_include_tests) {
+  config("rtc_unittests_config") {
+    # GN orders flags on a target before flags from configs. The default config
+    # adds -Wall, and this flag have to be after -Wall -- so they need to
+    # come from a config and can"t be on the target directly.
+    if (is_clang) {
+      cflags = [
+        "-Wno-sign-compare",
+        "-Wno-unused-const-variable",
+      ]
+    }
+  }
+
+  rtc_test("rtc_unittests") {
+    testonly = true
+
+    deps = [
+      ":webrtc_common",
+      "api:rtc_api_unittests",
+      "api/audio_codecs/test:audio_codecs_api_unittests",
+      "p2p:libstunprober_unittests",
+      "p2p:rtc_p2p_unittests",
+      "rtc_base:rtc_base_approved_unittests",
+      "rtc_base:rtc_base_tests_main",
+      "rtc_base:rtc_base_tests_utils",
+      "rtc_base:rtc_base_unittests",
+      "rtc_base:rtc_numerics_unittests",
+      "rtc_base:rtc_task_queue_unittests",
+      "rtc_base:sequenced_task_checker_unittests",
+      "rtc_base:weak_ptr_unittests",
+      "system_wrappers:metrics_default",
+    ]
+
+    if (rtc_enable_protobuf) {
+      deps += [ "logging:rtc_event_log_tests" ]
+    }
+
+    if (is_android) {
+      deps += [ "//testing/android/native_test:native_test_support" ]
+      shard_timeout = 900
+    }
+
+    if (is_ios || is_mac) {
+      deps += [ "sdk:sdk_unittests_objc" ]
+    }
+  }
+
+  # TODO(pbos): Rename test suite, this is no longer "just" for video targets.
+  video_engine_tests_resources = [
+    "../resources/foreman_cif_short.yuv",
+    "../resources/voice_engine/audio_long16.pcm",
+  ]
+
+  if (is_ios) {
+    bundle_data("video_engine_tests_bundle_data") {
+      testonly = true
+      sources = video_engine_tests_resources
+      outputs = [
+        "{{bundle_resources_dir}}/{{source_file_part}}",
+      ]
+    }
+  }
+
+  rtc_test("video_engine_tests") {
+    testonly = true
+    deps = [
+      "audio:audio_tests",
+
+      # TODO(eladalon): call_tests aren't actually video-specific, so we
+      # should move them to a more appropriate test suite.
+      "call:call_tests",
+      "modules/video_capture",
+      "rtc_base:rtc_base_tests_utils",
+      "test:test_common",
+      "test:test_main",
+      "test:video_test_common",
+      "video:video_tests",
+    ]
+    data = video_engine_tests_resources
+    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" ]
+    }
+    if (is_android) {
+      deps += [ "//testing/android/native_test:native_test_native_code" ]
+      shard_timeout = 900
+    }
+    if (is_ios) {
+      deps += [ ":video_engine_tests_bundle_data" ]
+    }
+  }
+
+  webrtc_perf_tests_resources = [
+    "../resources/audio_coding/speech_mono_16kHz.pcm",
+    "../resources/audio_coding/speech_mono_32_48kHz.pcm",
+    "../resources/audio_coding/testfile32kHz.pcm",
+    "../resources/ConferenceMotion_1280_720_50.yuv",
+    "../resources/difficult_photo_1850_1110.yuv",
+    "../resources/foreman_cif.yuv",
+    "../resources/google-wifi-3mbps.rx",
+    "../resources/paris_qcif.yuv",
+    "../resources/photo_1850_1110.yuv",
+    "../resources/presentation_1850_1110.yuv",
+    "../resources/verizon4g-downlink.rx",
+    "../resources/voice_engine/audio_long16.pcm",
+    "../resources/web_screenshot_1850_1110.yuv",
+  ]
+
+  if (is_ios) {
+    bundle_data("webrtc_perf_tests_bundle_data") {
+      testonly = true
+      sources = webrtc_perf_tests_resources
+      outputs = [
+        "{{bundle_resources_dir}}/{{source_file_part}}",
+      ]
+    }
+  }
+
+  rtc_test("webrtc_perf_tests") {
+    testonly = true
+    configs += [ ":rtc_unittests_config" ]
+
+    deps = [
+      "audio:audio_perf_tests",
+      "call:call_perf_tests",
+      "modules/audio_coding:audio_coding_perf_tests",
+      "modules/audio_processing:audio_processing_perf_tests",
+      "modules/remote_bitrate_estimator:remote_bitrate_estimator_perf_tests",
+      "test:test_main",
+      "video:video_full_stack_tests",
+    ]
+
+    data = webrtc_perf_tests_resources
+    if (is_android) {
+      deps += [ "//testing/android/native_test:native_test_native_code" ]
+      shard_timeout = 2700
+    }
+    if (is_ios) {
+      deps += [ ":webrtc_perf_tests_bundle_data" ]
+    }
+  }
+
+  rtc_test("webrtc_nonparallel_tests") {
+    testonly = true
+    deps = [
+      "rtc_base:rtc_base_nonparallel_tests",
+    ]
+    if (is_android) {
+      deps += [ "//testing/android/native_test:native_test_support" ]
+      shard_timeout = 900
+    }
+  }
+
+  if (is_android) {
+    junit_binary("android_junit_tests") {
+      java_files = [
+        "examples/androidjunit/src/org/appspot/apprtc/BluetoothManagerTest.java",
+        "examples/androidjunit/src/org/appspot/apprtc/DirectRTCClientTest.java",
+        "examples/androidjunit/src/org/appspot/apprtc/TCPChannelClientTest.java",
+        "sdk/android/tests/src/org/webrtc/CameraEnumerationTest.java",
+      ]
+
+      deps = [
+        "examples:AppRTCMobile_javalib",
+        "sdk/android:libjingle_peerconnection_java",
+        "//base:base_java_test_support",
+      ]
+    }
   }
 }