Revert "Export symbols needed by the Chromium component build (part 1)."

This reverts commit 9e24dcff167c4eb3555bf0ce6eaba090c10fbe53.

Reason for revert: Breaks chromium.webrtc.fyi bots.

Original change's description:
> Export symbols needed by the Chromium component build (part 1).
> 
> This CL uses RTC_EXPORT (defined in rtc_base/system/rtc_export.h)
> to mark WebRTC symbols as visible from a shared library, this doesn't
> mean these symbols are part of the public API (please continue to refer
> to [1] for info about what is considered public WebRTC API).
> 
> [1] - https://webrtc.googlesource.com/src/+/HEAD/native-api.md
> 
> Bug: webrtc:9419
> Change-Id: I802abd32874d42d3aa5ecd3c8022e7cf5e043d99
> Reviewed-on: https://webrtc-review.googlesource.com/c/103505
> Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
> Reviewed-by: Niels Moller <nisse@webrtc.org>
> Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#24969}

TBR=mbonadei@webrtc.org,kwiberg@webrtc.org,nisse@webrtc.org

Change-Id: I01f6e18f0d2c0f0309cdaa6c943c3927e1f1f49f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:9419
Reviewed-on: https://webrtc-review.googlesource.com/c/103720
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24974}
diff --git a/api/audio/BUILD.gn b/api/audio/BUILD.gn
index ce4838b..286a5a6 100644
--- a/api/audio/BUILD.gn
+++ b/api/audio/BUILD.gn
@@ -39,9 +39,6 @@
     "echo_canceller3_config.cc",
     "echo_canceller3_config.h",
   ]
-  deps = [
-    "../../rtc_base/system:rtc_export",
-  ]
 }
 
 rtc_source_set("aec3_factory") {
@@ -57,7 +54,6 @@
     ":echo_control",
     "../../modules/audio_processing/aec3",
     "../../rtc_base:rtc_base_approved",
-    "../../rtc_base/system:rtc_export",
     "//third_party/abseil-cpp/absl/memory",
   ]
 }
diff --git a/api/audio/echo_canceller3_config.h b/api/audio/echo_canceller3_config.h
index af0df23..e7376ed 100644
--- a/api/audio/echo_canceller3_config.h
+++ b/api/audio/echo_canceller3_config.h
@@ -13,12 +13,10 @@
 
 #include <stddef.h>  // size_t
 
-#include "rtc_base/system/rtc_export.h"
-
 namespace webrtc {
 
 // Configuration struct for EchoCanceller3
-struct RTC_EXPORT EchoCanceller3Config {
+struct EchoCanceller3Config {
   EchoCanceller3Config();
   EchoCanceller3Config(const EchoCanceller3Config& e);
   struct Delay {
diff --git a/api/audio/echo_canceller3_factory.h b/api/audio/echo_canceller3_factory.h
index 9052d99..f6db116 100644
--- a/api/audio/echo_canceller3_factory.h
+++ b/api/audio/echo_canceller3_factory.h
@@ -15,11 +15,10 @@
 
 #include "api/audio/echo_canceller3_config.h"
 #include "api/audio/echo_control.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 
-class RTC_EXPORT EchoCanceller3Factory : public EchoControlFactory {
+class EchoCanceller3Factory : public EchoControlFactory {
  public:
   // Factory producing EchoCanceller3 instances with the default configuration.
   EchoCanceller3Factory();
diff --git a/api/audio_codecs/L16/BUILD.gn b/api/audio_codecs/L16/BUILD.gn
index e362067..9724805 100644
--- a/api/audio_codecs/L16/BUILD.gn
+++ b/api/audio_codecs/L16/BUILD.gn
@@ -25,7 +25,6 @@
     "../../../modules/audio_coding:pcm16b",
     "../../../rtc_base:rtc_base_approved",
     "../../../rtc_base:safe_minmax",
-    "../../../rtc_base/system:rtc_export",
     "//third_party/abseil-cpp/absl/memory",
     "//third_party/abseil-cpp/absl/types:optional",
   ]
diff --git a/api/audio_codecs/L16/audio_encoder_L16.h b/api/audio_codecs/L16/audio_encoder_L16.h
index eef4da6..340e3af 100644
--- a/api/audio_codecs/L16/audio_encoder_L16.h
+++ b/api/audio_codecs/L16/audio_encoder_L16.h
@@ -18,7 +18,6 @@
 #include "api/audio_codecs/audio_codec_pair_id.h"
 #include "api/audio_codecs/audio_encoder.h"
 #include "api/audio_codecs/audio_format.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 
@@ -26,7 +25,7 @@
 // CreateAudioEncoderFactory<...>().
 //
 // NOTE: This struct is still under development and may change without notice.
-struct RTC_EXPORT AudioEncoderL16 {
+struct AudioEncoderL16 {
   struct Config {
     bool IsOk() const {
       return (sample_rate_hz == 8000 || sample_rate_hz == 16000 ||
diff --git a/api/audio_codecs/g711/BUILD.gn b/api/audio_codecs/g711/BUILD.gn
index 860ba3d..169172a 100644
--- a/api/audio_codecs/g711/BUILD.gn
+++ b/api/audio_codecs/g711/BUILD.gn
@@ -25,7 +25,6 @@
     "../../../modules/audio_coding:g711",
     "../../../rtc_base:rtc_base_approved",
     "../../../rtc_base:safe_minmax",
-    "../../../rtc_base/system:rtc_export",
     "//third_party/abseil-cpp/absl/memory",
     "//third_party/abseil-cpp/absl/types:optional",
   ]
diff --git a/api/audio_codecs/g711/audio_encoder_g711.h b/api/audio_codecs/g711/audio_encoder_g711.h
index 8dbc881..6b6eb5f 100644
--- a/api/audio_codecs/g711/audio_encoder_g711.h
+++ b/api/audio_codecs/g711/audio_encoder_g711.h
@@ -18,7 +18,6 @@
 #include "api/audio_codecs/audio_codec_pair_id.h"
 #include "api/audio_codecs/audio_encoder.h"
 #include "api/audio_codecs/audio_format.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 
@@ -26,7 +25,7 @@
 // CreateAudioEncoderFactory<...>().
 //
 // NOTE: This struct is still under development and may change without notice.
-struct RTC_EXPORT AudioEncoderG711 {
+struct AudioEncoderG711 {
   struct Config {
     enum class Type { kPcmU, kPcmA };
     bool IsOk() const {
diff --git a/api/audio_codecs/g722/BUILD.gn b/api/audio_codecs/g722/BUILD.gn
index d69596b..50b1396 100644
--- a/api/audio_codecs/g722/BUILD.gn
+++ b/api/audio_codecs/g722/BUILD.gn
@@ -33,7 +33,6 @@
     "../../../modules/audio_coding:g722",
     "../../../rtc_base:rtc_base_approved",
     "../../../rtc_base:safe_minmax",
-    "../../../rtc_base/system:rtc_export",
     "//third_party/abseil-cpp/absl/memory",
     "//third_party/abseil-cpp/absl/types:optional",
   ]
diff --git a/api/audio_codecs/g722/audio_encoder_g722.h b/api/audio_codecs/g722/audio_encoder_g722.h
index 3029e11..b97fe1b 100644
--- a/api/audio_codecs/g722/audio_encoder_g722.h
+++ b/api/audio_codecs/g722/audio_encoder_g722.h
@@ -19,7 +19,6 @@
 #include "api/audio_codecs/audio_encoder.h"
 #include "api/audio_codecs/audio_format.h"
 #include "api/audio_codecs/g722/audio_encoder_g722_config.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 
@@ -27,7 +26,7 @@
 // CreateAudioEncoderFactory<...>().
 //
 // NOTE: This struct is still under development and may change without notice.
-struct RTC_EXPORT AudioEncoderG722 {
+struct AudioEncoderG722 {
   using Config = AudioEncoderG722Config;
   static absl::optional<AudioEncoderG722Config> SdpToConfig(
       const SdpAudioFormat& audio_format);
diff --git a/api/audio_codecs/isac/BUILD.gn b/api/audio_codecs/isac/BUILD.gn
index e1bed07..ed9d962 100644
--- a/api/audio_codecs/isac/BUILD.gn
+++ b/api/audio_codecs/isac/BUILD.gn
@@ -131,7 +131,6 @@
     "../../..:webrtc_common",
     "../../../modules/audio_coding:isac",
     "../../../rtc_base:rtc_base_approved",
-    "../../../rtc_base/system:rtc_export",
     "//third_party/abseil-cpp/absl/memory",
     "//third_party/abseil-cpp/absl/types:optional",
   ]
diff --git a/api/audio_codecs/isac/audio_decoder_isac_float.h b/api/audio_codecs/isac/audio_decoder_isac_float.h
index b0793e4..cc13963 100644
--- a/api/audio_codecs/isac/audio_decoder_isac_float.h
+++ b/api/audio_codecs/isac/audio_decoder_isac_float.h
@@ -18,7 +18,6 @@
 #include "api/audio_codecs/audio_codec_pair_id.h"
 #include "api/audio_codecs/audio_decoder.h"
 #include "api/audio_codecs/audio_format.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 
@@ -26,7 +25,7 @@
 // parameter to CreateAudioDecoderFactory<...>().
 //
 // NOTE: This struct is still under development and may change without notice.
-struct RTC_EXPORT AudioDecoderIsacFloat {
+struct AudioDecoderIsacFloat {
   struct Config {
     bool IsOk() const {
       return sample_rate_hz == 16000 || sample_rate_hz == 32000;
diff --git a/api/audio_codecs/opus/BUILD.gn b/api/audio_codecs/opus/BUILD.gn
index 9c9bf33..800abbe 100644
--- a/api/audio_codecs/opus/BUILD.gn
+++ b/api/audio_codecs/opus/BUILD.gn
@@ -44,7 +44,6 @@
     "..:audio_codecs_api",
     "../../../modules/audio_coding:webrtc_opus",
     "../../../rtc_base:rtc_base_approved",
-    "../../../rtc_base/system:rtc_export",
     "//third_party/abseil-cpp/absl/types:optional",
   ]
 }
@@ -61,7 +60,6 @@
     "../../..:webrtc_common",
     "../../../modules/audio_coding:webrtc_opus",
     "../../../rtc_base:rtc_base_approved",
-    "../../../rtc_base/system:rtc_export",
     "//third_party/abseil-cpp/absl/memory",
     "//third_party/abseil-cpp/absl/types:optional",
   ]
diff --git a/api/audio_codecs/opus/audio_decoder_opus.h b/api/audio_codecs/opus/audio_decoder_opus.h
index 0fc720b..de26026 100644
--- a/api/audio_codecs/opus/audio_decoder_opus.h
+++ b/api/audio_codecs/opus/audio_decoder_opus.h
@@ -18,7 +18,6 @@
 #include "api/audio_codecs/audio_codec_pair_id.h"
 #include "api/audio_codecs/audio_decoder.h"
 #include "api/audio_codecs/audio_format.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 
@@ -26,7 +25,7 @@
 // CreateAudioDecoderFactory<...>().
 //
 // NOTE: This struct is still under development and may change without notice.
-struct RTC_EXPORT AudioDecoderOpus {
+struct AudioDecoderOpus {
   struct Config {
     int num_channels;
   };
diff --git a/api/audio_codecs/opus/audio_encoder_opus.h b/api/audio_codecs/opus/audio_encoder_opus.h
index bb4aa27..20aaaf7 100644
--- a/api/audio_codecs/opus/audio_encoder_opus.h
+++ b/api/audio_codecs/opus/audio_encoder_opus.h
@@ -19,7 +19,6 @@
 #include "api/audio_codecs/audio_encoder.h"
 #include "api/audio_codecs/audio_format.h"
 #include "api/audio_codecs/opus/audio_encoder_opus_config.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 
@@ -27,7 +26,7 @@
 // CreateAudioEncoderFactory<...>().
 //
 // NOTE: This struct is still under development and may change without notice.
-struct RTC_EXPORT AudioEncoderOpus {
+struct AudioEncoderOpus {
   using Config = AudioEncoderOpusConfig;
   static absl::optional<AudioEncoderOpusConfig> SdpToConfig(
       const SdpAudioFormat& audio_format);
diff --git a/media/BUILD.gn b/media/BUILD.gn
index cc203c6..858b272 100644
--- a/media/BUILD.gn
+++ b/media/BUILD.gn
@@ -136,7 +136,6 @@
     "../modules/audio_processing:audio_processing_statistics",
     "../rtc_base:rtc_base",
     "../rtc_base:rtc_base_approved",
-    "../rtc_base/system:rtc_export",
     "../rtc_base/third_party/sigslot",
     "//third_party/abseil-cpp/absl/types:optional",
   ]
diff --git a/media/base/rtputils.h b/media/base/rtputils.h
index c5fe14f..0fd9a59 100644
--- a/media/base/rtputils.h
+++ b/media/base/rtputils.h
@@ -12,7 +12,6 @@
 #define MEDIA_BASE_RTPUTILS_H_
 
 #include "rtc_base/byteorder.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace rtc {
 struct PacketTimeUpdateParams;
@@ -69,9 +68,9 @@
 const char* RtpRtcpStringLiteral(bool rtcp);
 
 // Verifies that a packet has a valid RTP header.
-bool RTC_EXPORT ValidateRtpHeader(const uint8_t* rtp,
-                                  size_t length,
-                                  size_t* header_length);
+bool ValidateRtpHeader(const uint8_t* rtp,
+                       size_t length,
+                       size_t* header_length);
 
 // Helper method which updates the absolute send time extension if present.
 bool UpdateRtpAbsSendTimeExtension(uint8_t* rtp,
@@ -81,11 +80,10 @@
 
 // Applies specified |options| to the packet. It updates the absolute send time
 // extension header if it is present present then updates HMAC.
-bool RTC_EXPORT
-ApplyPacketOptions(uint8_t* data,
-                   size_t length,
-                   const rtc::PacketTimeUpdateParams& packet_time_params,
-                   uint64_t time_us);
+bool ApplyPacketOptions(uint8_t* data,
+                        size_t length,
+                        const rtc::PacketTimeUpdateParams& packet_time_params,
+                        uint64_t time_us);
 
 }  // namespace cricket
 
diff --git a/media/base/turnutils.h b/media/base/turnutils.h
index 7aa0651..13ed26b 100644
--- a/media/base/turnutils.h
+++ b/media/base/turnutils.h
@@ -14,18 +14,16 @@
 #include <cstddef>
 #include <cstdint>
 
-#include "rtc_base/system/rtc_export.h"
-
 namespace cricket {
 
 struct PacketOptions;
 
 // Finds data location within a TURN Channel Message or TURN Send Indication
 // message.
-bool RTC_EXPORT UnwrapTurnPacket(const uint8_t* packet,
-                                 size_t packet_size,
-                                 size_t* content_position,
-                                 size_t* content_size);
+bool UnwrapTurnPacket(const uint8_t* packet,
+                      size_t packet_size,
+                      size_t* content_position,
+                      size_t* content_size);
 
 }  // namespace cricket
 
diff --git a/modules/audio_processing/BUILD.gn b/modules/audio_processing/BUILD.gn
index f84254b..6bff6cf 100644
--- a/modules/audio_processing/BUILD.gn
+++ b/modules/audio_processing/BUILD.gn
@@ -115,7 +115,6 @@
     "../../rtc_base:safe_minmax",
     "../../rtc_base:sanitizer",
     "../../rtc_base/system:arch",
-    "../../rtc_base/system:rtc_export",
     "../../system_wrappers:cpu_features_api",
     "../../system_wrappers:field_trial",
     "../../system_wrappers:metrics",
@@ -163,7 +162,6 @@
     "include/audio_processing_statistics.h",
   ]
   deps = [
-    "../../rtc_base/system:rtc_export",
     "//third_party/abseil-cpp/absl/types:optional",
   ]
 }
diff --git a/modules/audio_processing/aec_dump/BUILD.gn b/modules/audio_processing/aec_dump/BUILD.gn
index 5b55526..e5fee3e 100644
--- a/modules/audio_processing/aec_dump/BUILD.gn
+++ b/modules/audio_processing/aec_dump/BUILD.gn
@@ -17,7 +17,6 @@
   deps = [
     "../",
     "../../../rtc_base:rtc_base_approved",
-    "../../../rtc_base/system:rtc_export",
   ]
 }
 
diff --git a/modules/audio_processing/aec_dump/aec_dump_factory.h b/modules/audio_processing/aec_dump/aec_dump_factory.h
index 1e55d59..e3f00f6 100644
--- a/modules/audio_processing/aec_dump/aec_dump_factory.h
+++ b/modules/audio_processing/aec_dump/aec_dump_factory.h
@@ -16,7 +16,6 @@
 
 #include "modules/audio_processing/include/aec_dump.h"
 #include "rtc_base/platform_file.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace rtc {
 class TaskQueue;
@@ -24,7 +23,7 @@
 
 namespace webrtc {
 
-class RTC_EXPORT AecDumpFactory {
+class AecDumpFactory {
  public:
   // The |worker_queue| may not be null and must outlive the created
   // AecDump instance. |max_log_size_bytes == -1| means the log size
diff --git a/modules/audio_processing/include/audio_processing.h b/modules/audio_processing/include/audio_processing.h
index 8af0cb2..26880e3 100644
--- a/modules/audio_processing/include/audio_processing.h
+++ b/modules/audio_processing/include/audio_processing.h
@@ -34,7 +34,6 @@
 #include "rtc_base/platform_file.h"
 #include "rtc_base/refcount.h"
 #include "rtc_base/scoped_ref_ptr.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 
@@ -552,7 +551,7 @@
     float minimum_ = 0.0f;  // Long-term minimum.
   };
 
-  struct RTC_EXPORT AudioProcessingStatistics {
+  struct AudioProcessingStatistics {
     AudioProcessingStatistics();
     AudioProcessingStatistics(const AudioProcessingStatistics& other);
     ~AudioProcessingStatistics();
@@ -649,7 +648,7 @@
   static const int kChunkSizeMs = 10;
 };
 
-class RTC_EXPORT AudioProcessingBuilder {
+class AudioProcessingBuilder {
  public:
   AudioProcessingBuilder();
   ~AudioProcessingBuilder();
diff --git a/modules/audio_processing/include/audio_processing_statistics.h b/modules/audio_processing/include/audio_processing_statistics.h
index 2318bad..237d23c 100644
--- a/modules/audio_processing/include/audio_processing_statistics.h
+++ b/modules/audio_processing/include/audio_processing_statistics.h
@@ -12,12 +12,11 @@
 #define MODULES_AUDIO_PROCESSING_INCLUDE_AUDIO_PROCESSING_STATISTICS_H_
 
 #include "absl/types/optional.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 // This version of the stats uses Optionals, it will replace the regular
 // AudioProcessingStatistics struct.
-struct RTC_EXPORT AudioProcessingStats {
+struct AudioProcessingStats {
   AudioProcessingStats();
   AudioProcessingStats(const AudioProcessingStats& other);
   ~AudioProcessingStats();
diff --git a/modules/audio_processing/include/config.h b/modules/audio_processing/include/config.h
index e77d3fd..398aab6 100644
--- a/modules/audio_processing/include/config.h
+++ b/modules/audio_processing/include/config.h
@@ -14,7 +14,6 @@
 #include <map>
 
 #include "rtc_base/constructormagic.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 
@@ -58,7 +57,7 @@
 //    config.Set<Algo1_CostFunction>(new SqrCost());
 //
 // Note: This class is thread-compatible (like STL containers).
-class RTC_EXPORT Config {
+class Config {
  public:
   // Returns the option if set or a default constructed one.
   // Callers that access options too often are encouraged to cache the result.
diff --git a/modules/audio_processing/typing_detection.h b/modules/audio_processing/typing_detection.h
index d8fb359..70fd9033 100644
--- a/modules/audio_processing/typing_detection.h
+++ b/modules/audio_processing/typing_detection.h
@@ -11,11 +11,9 @@
 #ifndef MODULES_AUDIO_PROCESSING_TYPING_DETECTION_H_
 #define MODULES_AUDIO_PROCESSING_TYPING_DETECTION_H_
 
-#include "rtc_base/system/rtc_export.h"
-
 namespace webrtc {
 
-class RTC_EXPORT TypingDetection {
+class TypingDetection {
  public:
   TypingDetection();
   virtual ~TypingDetection();
diff --git a/modules/desktop_capture/BUILD.gn b/modules/desktop_capture/BUILD.gn
index 207f1d4..74de174 100644
--- a/modules/desktop_capture/BUILD.gn
+++ b/modules/desktop_capture/BUILD.gn
@@ -30,7 +30,6 @@
   deps = [
     "../..:webrtc_common",
     "../../rtc_base:checks",
-    "../../rtc_base/system:rtc_export",
     "//third_party/abseil-cpp/absl/memory",
   ]
 
@@ -377,7 +376,6 @@
     "../../rtc_base:rtc_base",  # TODO(kjellander): Cleanup in bugs.webrtc.org/3806.
     "../../rtc_base/synchronization:rw_lock_wrapper",
     "../../rtc_base/system:arch",
-    "../../rtc_base/system:rtc_export",
     "../../system_wrappers",
     "../../system_wrappers:cpu_features_api",
     "../../system_wrappers:metrics",
diff --git a/modules/desktop_capture/cropped_desktop_frame.h b/modules/desktop_capture/cropped_desktop_frame.h
index 6782398..59dced4 100644
--- a/modules/desktop_capture/cropped_desktop_frame.h
+++ b/modules/desktop_capture/cropped_desktop_frame.h
@@ -12,7 +12,6 @@
 #define MODULES_DESKTOP_CAPTURE_CROPPED_DESKTOP_FRAME_H_
 
 #include "modules/desktop_capture/desktop_frame.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 
@@ -21,9 +20,9 @@
 // |frame| should not be nullptr. |rect| is in |frame| coordinate, i.e.
 // |frame|->top_left() does not impact the area of |rect|.
 // Returns nullptr frame if |rect| is not contained by the bounds of |frame|.
-std::unique_ptr<DesktopFrame> RTC_EXPORT
-CreateCroppedDesktopFrame(std::unique_ptr<DesktopFrame> frame,
-                          const DesktopRect& rect);
+std::unique_ptr<DesktopFrame> CreateCroppedDesktopFrame(
+    std::unique_ptr<DesktopFrame> frame,
+    const DesktopRect& rect);
 
 }  // namespace webrtc
 
diff --git a/modules/desktop_capture/cropping_window_capturer.h b/modules/desktop_capture/cropping_window_capturer.h
index 224198f..c889801 100644
--- a/modules/desktop_capture/cropping_window_capturer.h
+++ b/modules/desktop_capture/cropping_window_capturer.h
@@ -15,15 +15,14 @@
 
 #include "modules/desktop_capture/desktop_capture_options.h"
 #include "modules/desktop_capture/desktop_capturer.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 
 // WindowCapturer implementation that uses a screen capturer to capture the
 // whole screen and crops the video frame to the window area when the captured
 // window is on top.
-class RTC_EXPORT CroppingWindowCapturer : public DesktopCapturer,
-                                          public DesktopCapturer::Callback {
+class CroppingWindowCapturer : public DesktopCapturer,
+                               public DesktopCapturer::Callback {
  public:
   static std::unique_ptr<DesktopCapturer> CreateCapturer(
       const DesktopCaptureOptions& options);
diff --git a/modules/desktop_capture/desktop_and_cursor_composer.h b/modules/desktop_capture/desktop_and_cursor_composer.h
index fa5d15c..7dff710 100644
--- a/modules/desktop_capture/desktop_and_cursor_composer.h
+++ b/modules/desktop_capture/desktop_and_cursor_composer.h
@@ -17,16 +17,14 @@
 #include "modules/desktop_capture/desktop_capturer.h"
 #include "modules/desktop_capture/mouse_cursor_monitor.h"
 #include "rtc_base/constructormagic.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 
 // A wrapper for DesktopCapturer that also captures mouse using specified
 // MouseCursorMonitor and renders it on the generated streams.
-class RTC_EXPORT DesktopAndCursorComposer
-    : public DesktopCapturer,
-      public DesktopCapturer::Callback,
-      public MouseCursorMonitor::Callback {
+class DesktopAndCursorComposer : public DesktopCapturer,
+                                 public DesktopCapturer::Callback,
+                                 public MouseCursorMonitor::Callback {
  public:
   // Creates a new blender that captures mouse cursor using
   // MouseCursorMonitor::Create(options) and renders it into the frames
diff --git a/modules/desktop_capture/desktop_capture_options.h b/modules/desktop_capture/desktop_capture_options.h
index 44ba79d..60aa05c 100644
--- a/modules/desktop_capture/desktop_capture_options.h
+++ b/modules/desktop_capture/desktop_capture_options.h
@@ -12,7 +12,6 @@
 
 #include "rtc_base/constructormagic.h"
 #include "rtc_base/scoped_ref_ptr.h"
-#include "rtc_base/system/rtc_export.h"
 
 #if defined(USE_X11)
 #include "modules/desktop_capture/x11/shared_x_display.h"
@@ -27,7 +26,7 @@
 
 // An object that stores initialization parameters for screen and window
 // capturers.
-class RTC_EXPORT DesktopCaptureOptions {
+class DesktopCaptureOptions {
  public:
   // Returns instance of DesktopCaptureOptions with default parameters. On Linux
   // also initializes X window connection. x_display() will be set to null if
diff --git a/modules/desktop_capture/desktop_capturer.h b/modules/desktop_capture/desktop_capturer.h
index effe0df..47196cf 100644
--- a/modules/desktop_capture/desktop_capturer.h
+++ b/modules/desktop_capture/desktop_capturer.h
@@ -22,7 +22,6 @@
 #include "modules/desktop_capture/desktop_capture_types.h"
 #include "modules/desktop_capture/desktop_frame.h"
 #include "modules/desktop_capture/shared_memory.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 
@@ -30,7 +29,7 @@
 class DesktopFrame;
 
 // Abstract interface for screen and window capturers.
-class RTC_EXPORT DesktopCapturer {
+class DesktopCapturer {
  public:
   enum class Result {
     // The frame was captured successfully.
diff --git a/modules/desktop_capture/desktop_frame.h b/modules/desktop_capture/desktop_frame.h
index 29b84b7..6f7edfc 100644
--- a/modules/desktop_capture/desktop_frame.h
+++ b/modules/desktop_capture/desktop_frame.h
@@ -18,14 +18,13 @@
 #include "modules/desktop_capture/desktop_region.h"
 #include "modules/desktop_capture/shared_memory.h"
 #include "rtc_base/constructormagic.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 
 const int kStandardDPI = 96;
 
 // DesktopFrame represents a video frame captured from the screen.
-class RTC_EXPORT DesktopFrame {
+class DesktopFrame {
  public:
   // DesktopFrame objects always hold RGBA data.
   static const int kBytesPerPixel = 4;
@@ -136,7 +135,7 @@
 };
 
 // A DesktopFrame that stores data in the heap.
-class RTC_EXPORT BasicDesktopFrame : public DesktopFrame {
+class BasicDesktopFrame : public DesktopFrame {
  public:
   explicit BasicDesktopFrame(DesktopSize size);
 
diff --git a/modules/desktop_capture/fake_desktop_capturer.h b/modules/desktop_capture/fake_desktop_capturer.h
index fd867e3..82c053c 100644
--- a/modules/desktop_capture/fake_desktop_capturer.h
+++ b/modules/desktop_capture/fake_desktop_capturer.h
@@ -17,7 +17,6 @@
 #include "modules/desktop_capture/desktop_capturer.h"
 #include "modules/desktop_capture/desktop_frame_generator.h"
 #include "modules/desktop_capture/shared_memory.h"
-#include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
 
@@ -32,7 +31,7 @@
 // Double buffering is guaranteed by the FrameGenerator. FrameGenerator
 // implements in desktop_frame_generator.h guarantee double buffering, they
 // creates a new instance of DesktopFrame each time.
-class RTC_EXPORT FakeDesktopCapturer : public DesktopCapturer {
+class FakeDesktopCapturer : public DesktopCapturer {
  public:
   FakeDesktopCapturer();
   ~FakeDesktopCapturer() override;
diff --git a/rtc_base/BUILD.gn b/rtc_base/BUILD.gn
index 9deec5d..e9efbd1 100644
--- a/rtc_base/BUILD.gn
+++ b/rtc_base/BUILD.gn
@@ -529,7 +529,6 @@
   deps = [
     ":macromagic",
     ":ptr_util",
-    "system:rtc_export",
     "//third_party/abseil-cpp/absl/memory",
   ]
 }
diff --git a/rtc_base/task_queue.h b/rtc_base/task_queue.h
index 888e203..b8b307c 100644
--- a/rtc_base/task_queue.h
+++ b/rtc_base/task_queue.h
@@ -18,7 +18,6 @@
 #include "absl/memory/memory.h"
 #include "rtc_base/constructormagic.h"
 #include "rtc_base/scoped_ref_ptr.h"
-#include "rtc_base/system/rtc_export.h"
 #include "rtc_base/thread_annotations.h"
 
 namespace rtc {
@@ -151,7 +150,7 @@
 // TaskQueue itself has been deleted or it may happen synchronously while the
 // TaskQueue instance is being deleted.  This may vary from one OS to the next
 // so assumptions about lifetimes of pending tasks should not be made.
-class RTC_LOCKABLE RTC_EXPORT TaskQueue {
+class RTC_LOCKABLE TaskQueue {
  public:
   // TaskQueue priority levels. On some platforms these will map to thread
   // priorities, on others such as Mac and iOS, GCD queue priorities.