Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

13 files changed, 606 insertions, 0 deletions

diff --git a/third_party/libwebrtc/sdk/objc/helpers/AVCaptureSession+DevicePosition.h b/third_party/libwebrtc/sdk/objc/helpers/AVCaptureSession+DevicePosition.h
new file mode 100644
index 0000000000..32ab6877f0
--- /dev/null
+++ b/third_party/libwebrtc/sdk/objc/helpers/AVCaptureSession+DevicePosition.h
@@ -0,0 +1,23 @@
+/*
+ *  Copyright 2017 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 <AVFoundation/AVFoundation.h>
+#import <CoreMedia/CoreMedia.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface AVCaptureSession (DevicePosition)
+
+// Check the image's EXIF for the camera the image came from.
++ (AVCaptureDevicePosition)devicePositionForSampleBuffer:(CMSampleBufferRef)sampleBuffer;
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/third_party/libwebrtc/sdk/objc/helpers/AVCaptureSession+DevicePosition.mm b/third_party/libwebrtc/sdk/objc/helpers/AVCaptureSession+DevicePosition.mm
new file mode 100644
index 0000000000..0814ecc6c5
--- /dev/null
+++ b/third_party/libwebrtc/sdk/objc/helpers/AVCaptureSession+DevicePosition.mm
@@ -0,0 +1,51 @@
+/*
+ *  Copyright 2017 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 "AVCaptureSession+DevicePosition.h"
+
+BOOL CFStringContainsString(CFStringRef theString, CFStringRef stringToFind) {
+  return CFStringFindWithOptions(theString,
+                                 stringToFind,
+                                 CFRangeMake(0, CFStringGetLength(theString)),
+                                 kCFCompareCaseInsensitive,
+                                 nil);
+}
+
+@implementation AVCaptureSession (DevicePosition)
+
++ (AVCaptureDevicePosition)devicePositionForSampleBuffer:(CMSampleBufferRef)sampleBuffer {
+  // Check the image's EXIF for the camera the image came from.
+  AVCaptureDevicePosition cameraPosition = AVCaptureDevicePositionUnspecified;
+  CFDictionaryRef attachments = CMCopyDictionaryOfAttachments(
+      kCFAllocatorDefault, sampleBuffer, kCMAttachmentMode_ShouldPropagate);
+  if (attachments) {
+    int size = CFDictionaryGetCount(attachments);
+    if (size > 0) {
+      CFDictionaryRef cfExifDictVal = nil;
+      if (CFDictionaryGetValueIfPresent(
+              attachments, (const void *)CFSTR("{Exif}"), (const void **)&cfExifDictVal)) {
+        CFStringRef cfLensModelStrVal;
+        if (CFDictionaryGetValueIfPresent(cfExifDictVal,
+                                          (const void *)CFSTR("LensModel"),
+                                          (const void **)&cfLensModelStrVal)) {
+          if (CFStringContainsString(cfLensModelStrVal, CFSTR("front"))) {
+            cameraPosition = AVCaptureDevicePositionFront;
+          } else if (CFStringContainsString(cfLensModelStrVal, CFSTR("back"))) {
+            cameraPosition = AVCaptureDevicePositionBack;
+          }
+        }
+      }
+    }
+    CFRelease(attachments);
+  }
+  return cameraPosition;
+}
+
+@end
diff --git a/third_party/libwebrtc/sdk/objc/helpers/NSString+StdString.h b/third_party/libwebrtc/sdk/objc/helpers/NSString+StdString.h
new file mode 100644
index 0000000000..b0324e8a19
--- /dev/null
+++ b/third_party/libwebrtc/sdk/objc/helpers/NSString+StdString.h
@@ -0,0 +1,34 @@
+/*
+ *  Copyright 2015 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 <Foundation/Foundation.h>
+
+#include <string>
+
+#include "absl/strings/string_view.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface NSString (StdString)
+
+@property(nonatomic, readonly) std::string stdString;
+
++ (std::string)stdStringForString:(NSString *)nsString;
++ (NSString *)stringForStdString:(const std::string &)stdString;
+
+@end
+
+@interface NSString (AbslStringView)
+
++ (NSString *)stringForAbslStringView:(const absl::string_view)abslStringView;
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/third_party/libwebrtc/sdk/objc/helpers/NSString+StdString.mm b/third_party/libwebrtc/sdk/objc/helpers/NSString+StdString.mm
new file mode 100644
index 0000000000..c98432c445
--- /dev/null
+++ b/third_party/libwebrtc/sdk/objc/helpers/NSString+StdString.mm
@@ -0,0 +1,45 @@
+/*
+ *  Copyright 2015 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 "NSString+StdString.h"
+
+#include "absl/strings/string_view.h"
+
+@implementation NSString (StdString)
+
+- (std::string)stdString {
+  return [NSString stdStringForString:self];
+}
+
++ (std::string)stdStringForString:(NSString *)nsString {
+  NSData *charData = [nsString dataUsingEncoding:NSUTF8StringEncoding];
+  return std::string(reinterpret_cast<const char *>(charData.bytes),
+                     charData.length);
+}
+
++ (NSString *)stringForStdString:(const std::string&)stdString {
+  // std::string may contain null termination character so we construct
+  // using length.
+  return [[NSString alloc] initWithBytes:stdString.data()
+                                  length:stdString.length()
+                                encoding:NSUTF8StringEncoding];
+}
+
+@end
+
+@implementation NSString (AbslStringView)
+
++ (NSString *)stringForAbslStringView:(const absl::string_view)abslStringView {
+  return [[NSString alloc] initWithBytes:abslStringView.data()
+                                  length:abslStringView.length()
+                                encoding:NSUTF8StringEncoding];
+}
+
+@end
diff --git a/third_party/libwebrtc/sdk/objc/helpers/RTCCameraPreviewView.h b/third_party/libwebrtc/sdk/objc/helpers/RTCCameraPreviewView.h
new file mode 100644
index 0000000000..db9b15a45c
--- /dev/null
+++ b/third_party/libwebrtc/sdk/objc/helpers/RTCCameraPreviewView.h
@@ -0,0 +1,30 @@
+/*
+ *  Copyright 2015 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 <Foundation/Foundation.h>
+#import <UIKit/UIKit.h>
+
+#import "RTCMacros.h"
+
+@class AVCaptureSession;
+
+/** RTCCameraPreviewView is a view that renders local video from an
+ *  AVCaptureSession.
+ */
+RTC_OBJC_EXPORT
+@interface RTC_OBJC_TYPE (RTCCameraPreviewView) : UIView
+
+/** The capture session being rendered in the view. Capture session
+ *  is assigned to AVCaptureVideoPreviewLayer async in the same
+ *  queue that the AVCaptureSession is started/stopped.
+ */
+@property(nonatomic, strong) AVCaptureSession* captureSession;
+
+@end
diff --git a/third_party/libwebrtc/sdk/objc/helpers/RTCCameraPreviewView.m b/third_party/libwebrtc/sdk/objc/helpers/RTCCameraPreviewView.m
new file mode 100644
index 0000000000..12e87d8d64
--- /dev/null
+++ b/third_party/libwebrtc/sdk/objc/helpers/RTCCameraPreviewView.m
@@ -0,0 +1,123 @@
+/*
+ *  Copyright 2015 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 "RTCCameraPreviewView.h"
+
+#import <AVFoundation/AVFoundation.h>
+#import <UIKit/UIKit.h>
+
+#import "RTCDispatcher+Private.h"
+
+@implementation RTC_OBJC_TYPE (RTCCameraPreviewView)
+
+@synthesize captureSession = _captureSession;
+
++ (Class)layerClass {
+  return [AVCaptureVideoPreviewLayer class];
+}
+
+- (instancetype)initWithFrame:(CGRect)aRect {
+  self = [super initWithFrame:aRect];
+  if (self) {
+    [self addOrientationObserver];
+  }
+  return self;
+}
+
+- (instancetype)initWithCoder:(NSCoder*)aDecoder {
+  self = [super initWithCoder:aDecoder];
+  if (self) {
+    [self addOrientationObserver];
+  }
+  return self;
+}
+
+- (void)dealloc {
+  [self removeOrientationObserver];
+}
+
+- (void)setCaptureSession:(AVCaptureSession *)captureSession {
+  if (_captureSession == captureSession) {
+    return;
+  }
+  _captureSession = captureSession;
+  [RTC_OBJC_TYPE(RTCDispatcher)
+      dispatchAsyncOnType:RTCDispatcherTypeMain
+                    block:^{
+                      AVCaptureVideoPreviewLayer *previewLayer = [self previewLayer];
+                      [RTC_OBJC_TYPE(RTCDispatcher)
+                          dispatchAsyncOnType:RTCDispatcherTypeCaptureSession
+                                        block:^{
+                                          previewLayer.session = captureSession;
+                                          [RTC_OBJC_TYPE(RTCDispatcher)
+                                              dispatchAsyncOnType:RTCDispatcherTypeMain
+                                                            block:^{
+                                                              [self setCorrectVideoOrientation];
+                                                            }];
+                                        }];
+                    }];
+}
+
+- (void)layoutSubviews {
+  [super layoutSubviews];
+
+  // Update the video orientation based on the device orientation.
+  [self setCorrectVideoOrientation];
+}
+
+-(void)orientationChanged:(NSNotification *)notification {
+  [self setCorrectVideoOrientation];
+}
+
+- (void)setCorrectVideoOrientation {
+  // Get current device orientation.
+  UIDeviceOrientation deviceOrientation = [UIDevice currentDevice].orientation;
+  AVCaptureVideoPreviewLayer *previewLayer = [self previewLayer];
+
+  // First check if we are allowed to set the video orientation.
+  if (previewLayer.connection.isVideoOrientationSupported) {
+    // Set the video orientation based on device orientation.
+    if (deviceOrientation == UIInterfaceOrientationPortraitUpsideDown) {
+      previewLayer.connection.videoOrientation =
+          AVCaptureVideoOrientationPortraitUpsideDown;
+    } else if (deviceOrientation == UIInterfaceOrientationLandscapeRight) {
+      previewLayer.connection.videoOrientation =
+          AVCaptureVideoOrientationLandscapeRight;
+    } else if (deviceOrientation == UIInterfaceOrientationLandscapeLeft) {
+      previewLayer.connection.videoOrientation =
+          AVCaptureVideoOrientationLandscapeLeft;
+    } else if (deviceOrientation == UIInterfaceOrientationPortrait) {
+      previewLayer.connection.videoOrientation =
+          AVCaptureVideoOrientationPortrait;
+    }
+    // If device orientation switches to FaceUp or FaceDown, don't change video orientation.
+  }
+}
+
+#pragma mark - Private
+
+- (void)addOrientationObserver {
+  [[NSNotificationCenter defaultCenter] addObserver:self
+                                            selector:@selector(orientationChanged:)
+                                                name:UIDeviceOrientationDidChangeNotification
+                                              object:nil];
+}
+
+- (void)removeOrientationObserver {
+  [[NSNotificationCenter defaultCenter] removeObserver:self
+                                                  name:UIDeviceOrientationDidChangeNotification
+                                                object:nil];
+}
+
+- (AVCaptureVideoPreviewLayer *)previewLayer {
+  return (AVCaptureVideoPreviewLayer *)self.layer;
+}
+
+@end
diff --git a/third_party/libwebrtc/sdk/objc/helpers/RTCDispatcher+Private.h b/third_party/libwebrtc/sdk/objc/helpers/RTCDispatcher+Private.h
new file mode 100644
index 0000000000..195c651790
--- /dev/null
+++ b/third_party/libwebrtc/sdk/objc/helpers/RTCDispatcher+Private.h
@@ -0,0 +1,18 @@
+/*
+ *  Copyright 2015 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 "RTCDispatcher.h"
+
+@interface RTC_OBJC_TYPE (RTCDispatcher)
+()
+
+    + (dispatch_queue_t)dispatchQueueForType : (RTCDispatcherQueueType)dispatchType;
+
+@end
diff --git a/third_party/libwebrtc/sdk/objc/helpers/RTCDispatcher.h b/third_party/libwebrtc/sdk/objc/helpers/RTCDispatcher.h
new file mode 100644
index 0000000000..e148af6dea
--- /dev/null
+++ b/third_party/libwebrtc/sdk/objc/helpers/RTCDispatcher.h
@@ -0,0 +1,46 @@
+/*
+ *  Copyright 2015 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 <Foundation/Foundation.h>
+
+#import "RTCMacros.h"
+
+typedef NS_ENUM(NSInteger, RTCDispatcherQueueType) {
+  // Main dispatcher queue.
+  RTCDispatcherTypeMain,
+  // Used for starting/stopping AVCaptureSession, and assigning
+  // capture session to AVCaptureVideoPreviewLayer.
+  RTCDispatcherTypeCaptureSession,
+  // Used for operations on AVAudioSession.
+  RTCDispatcherTypeAudioSession,
+  // Used for operations on NWPathMonitor.
+  RTCDispatcherTypeNetworkMonitor,
+};
+
+/** Dispatcher that asynchronously dispatches blocks to a specific
+ *  shared dispatch queue.
+ */
+RTC_OBJC_EXPORT
+@interface RTC_OBJC_TYPE (RTCDispatcher) : NSObject
+
+- (instancetype)init NS_UNAVAILABLE;
+
+/** Dispatch the block asynchronously on the queue for dispatchType.
+ *  @param dispatchType The queue type to dispatch on.
+ *  @param block The block to dispatch asynchronously.
+ */
++ (void)dispatchAsyncOnType:(RTCDispatcherQueueType)dispatchType block:(dispatch_block_t)block;
+
+/** Returns YES if run on queue for the dispatchType otherwise NO.
+ *  Useful for asserting that a method is run on a correct queue.
+ */
++ (BOOL)isOnQueueForType:(RTCDispatcherQueueType)dispatchType;
+
+@end
diff --git a/third_party/libwebrtc/sdk/objc/helpers/RTCDispatcher.m b/third_party/libwebrtc/sdk/objc/helpers/RTCDispatcher.m
new file mode 100644
index 0000000000..4df19bc297
--- /dev/null
+++ b/third_party/libwebrtc/sdk/objc/helpers/RTCDispatcher.m
@@ -0,0 +1,65 @@
+/*
+ *  Copyright 2015 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 "RTCDispatcher+Private.h"
+
+static dispatch_queue_t kAudioSessionQueue = nil;
+static dispatch_queue_t kCaptureSessionQueue = nil;
+static dispatch_queue_t kNetworkMonitorQueue = nil;
+
+@implementation RTC_OBJC_TYPE (RTCDispatcher)
+
++ (void)initialize {
+  static dispatch_once_t onceToken;
+  dispatch_once(&onceToken, ^{
+    kAudioSessionQueue = dispatch_queue_create(
+        "org.webrtc.RTCDispatcherAudioSession",
+        DISPATCH_QUEUE_SERIAL);
+    kCaptureSessionQueue = dispatch_queue_create(
+        "org.webrtc.RTCDispatcherCaptureSession",
+        DISPATCH_QUEUE_SERIAL);
+    kNetworkMonitorQueue =
+        dispatch_queue_create("org.webrtc.RTCDispatcherNetworkMonitor", DISPATCH_QUEUE_SERIAL);
+  });
+}
+
++ (void)dispatchAsyncOnType:(RTCDispatcherQueueType)dispatchType
+                      block:(dispatch_block_t)block {
+  dispatch_queue_t queue = [self dispatchQueueForType:dispatchType];
+  dispatch_async(queue, block);
+}
+
++ (BOOL)isOnQueueForType:(RTCDispatcherQueueType)dispatchType {
+  dispatch_queue_t targetQueue = [self dispatchQueueForType:dispatchType];
+  const char* targetLabel = dispatch_queue_get_label(targetQueue);
+  const char* currentLabel = dispatch_queue_get_label(DISPATCH_CURRENT_QUEUE_LABEL);
+
+  NSAssert(strlen(targetLabel) > 0, @"Label is required for the target queue.");
+  NSAssert(strlen(currentLabel) > 0, @"Label is required for the current queue.");
+
+  return strcmp(targetLabel, currentLabel) == 0;
+}
+
+#pragma mark - Private
+
++ (dispatch_queue_t)dispatchQueueForType:(RTCDispatcherQueueType)dispatchType {
+  switch (dispatchType) {
+    case RTCDispatcherTypeMain:
+      return dispatch_get_main_queue();
+    case RTCDispatcherTypeCaptureSession:
+      return kCaptureSessionQueue;
+    case RTCDispatcherTypeAudioSession:
+      return kAudioSessionQueue;
+    case RTCDispatcherTypeNetworkMonitor:
+      return kNetworkMonitorQueue;
+  }
+}
+
+@end
diff --git a/third_party/libwebrtc/sdk/objc/helpers/UIDevice+RTCDevice.h b/third_party/libwebrtc/sdk/objc/helpers/UIDevice+RTCDevice.h
new file mode 100644
index 0000000000..4d04f38f8c
--- /dev/null
+++ b/third_party/libwebrtc/sdk/objc/helpers/UIDevice+RTCDevice.h
@@ -0,0 +1,17 @@
+/*
+ *  Copyright 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.
+ */
+
+#import <UIKit/UIKit.h>
+
+@interface UIDevice (RTCDevice)
+
++ (NSString *)machineName;
+
+@end
diff --git a/third_party/libwebrtc/sdk/objc/helpers/UIDevice+RTCDevice.mm b/third_party/libwebrtc/sdk/objc/helpers/UIDevice+RTCDevice.mm
new file mode 100644
index 0000000000..f3c21991b8
--- /dev/null
+++ b/third_party/libwebrtc/sdk/objc/helpers/UIDevice+RTCDevice.mm
@@ -0,0 +1,25 @@
+/*
+ *  Copyright 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.
+ */
+
+#import "UIDevice+RTCDevice.h"
+
+#import <sys/utsname.h>
+#include <memory>
+
+@implementation UIDevice (RTCDevice)
+
++ (NSString *)machineName {
+  struct utsname systemInfo;
+  uname(&systemInfo);
+  return [[NSString alloc] initWithCString:systemInfo.machine
+                                  encoding:NSUTF8StringEncoding];
+}
+
+@end
diff --git a/third_party/libwebrtc/sdk/objc/helpers/noop.mm b/third_party/libwebrtc/sdk/objc/helpers/noop.mm
new file mode 100644
index 0000000000..16a8e6d5c1
--- /dev/null
+++ b/third_party/libwebrtc/sdk/objc/helpers/noop.mm
@@ -0,0 +1,13 @@
+/*
+ *  Copyright 2015 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.
+ */
+
+// This file is only needed to make ninja happy on some platforms.
+// On some platforms it is not possible to link an rtc_static_library
+// without any source file listed in the GN target.
diff --git a/third_party/libwebrtc/sdk/objc/helpers/scoped_cftyperef.h b/third_party/libwebrtc/sdk/objc/helpers/scoped_cftyperef.h
new file mode 100644
index 0000000000..092f02b3af
--- /dev/null
+++ b/third_party/libwebrtc/sdk/objc/helpers/scoped_cftyperef.h
@@ -0,0 +1,116 @@
+/*
+ *  Copyright (c) 2017 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 SDK_OBJC_HELPERS_SCOPED_CFTYPEREF_H_
+#define SDK_OBJC_HELPERS_SCOPED_CFTYPEREF_H_
+
+#include <CoreFoundation/CoreFoundation.h>
+namespace rtc {
+
+// RETAIN: ScopedTypeRef should retain the object when it takes
+// ownership.
+// ASSUME: Assume the object already has already been retained.
+// ScopedTypeRef takes over ownership.
+enum class RetainPolicy { RETAIN, ASSUME };
+
+namespace internal {
+template <typename T>
+struct CFTypeRefTraits {
+  static T InvalidValue() { return nullptr; }
+  static void Release(T ref) { CFRelease(ref); }
+  static T Retain(T ref) {
+    CFRetain(ref);
+    return ref;
+  }
+};
+
+template <typename T, typename Traits>
+class ScopedTypeRef {
+ public:
+  ScopedTypeRef() : ptr_(Traits::InvalidValue()) {}
+  explicit ScopedTypeRef(T ptr) : ptr_(ptr) {}
+  ScopedTypeRef(T ptr, RetainPolicy policy) : ScopedTypeRef(ptr) {
+    if (ptr_ && policy == RetainPolicy::RETAIN)
+      Traits::Retain(ptr_);
+  }
+
+  ScopedTypeRef(const ScopedTypeRef<T, Traits>& rhs) : ptr_(rhs.ptr_) {
+    if (ptr_)
+      ptr_ = Traits::Retain(ptr_);
+  }
+
+  ~ScopedTypeRef() {
+    if (ptr_) {
+      Traits::Release(ptr_);
+    }
+  }
+
+  T get() const { return ptr_; }
+  T operator->() const { return ptr_; }
+  explicit operator bool() const { return ptr_; }
+
+  bool operator!() const { return !ptr_; }
+
+  ScopedTypeRef& operator=(const T& rhs) {
+    if (ptr_)
+      Traits::Release(ptr_);
+    ptr_ = rhs;
+    return *this;
+  }
+
+  ScopedTypeRef& operator=(const ScopedTypeRef<T, Traits>& rhs) {
+    reset(rhs.get(), RetainPolicy::RETAIN);
+    return *this;
+  }
+
+  // This is intended to take ownership of objects that are
+  // created by pass-by-pointer initializers.
+  T* InitializeInto() {
+    RTC_DCHECK(!ptr_);
+    return &ptr_;
+  }
+
+  void reset(T ptr, RetainPolicy policy = RetainPolicy::ASSUME) {
+    if (ptr && policy == RetainPolicy::RETAIN)
+      Traits::Retain(ptr);
+    if (ptr_)
+      Traits::Release(ptr_);
+    ptr_ = ptr;
+  }
+
+  T release() {
+    T temp = ptr_;
+    ptr_ = Traits::InvalidValue();
+    return temp;
+  }
+
+ private:
+  T ptr_;
+};
+}  // namespace internal
+
+template <typename T>
+using ScopedCFTypeRef =
+    internal::ScopedTypeRef<T, internal::CFTypeRefTraits<T>>;
+
+template <typename T>
+static ScopedCFTypeRef<T> AdoptCF(T cftype) {
+  return ScopedCFTypeRef<T>(cftype, RetainPolicy::RETAIN);
+}
+
+template <typename T>
+static ScopedCFTypeRef<T> ScopedCF(T cftype) {
+  return ScopedCFTypeRef<T>(cftype);
+}
+
+}  // namespace rtc
+
+#endif  // SDK_OBJC_HELPERS_SCOPED_CFTYPEREF_H_