Add unit test class for RTCCameraVideoCapturer.

webrtc/sdk/objc/Framework/Classes/RTCCameraVideoCapturer.m

Index: webrtc/sdk/objc/Framework/Classes/RTCCameraVideoCapturer.m
diff --git a/webrtc/sdk/objc/Framework/Classes/RTCCameraVideoCapturer.m b/webrtc/sdk/objc/Framework/Classes/RTCCameraVideoCapturer.m
index 16ddc13c9eaba1f5aaf42176a66c5444a4740e3e..de092e6da4ec5bd4837b31154c8751dce990ea13 100644
--- a/webrtc/sdk/objc/Framework/Classes/RTCCameraVideoCapturer.m
+++ b/webrtc/sdk/objc/Framework/Classes/RTCCameraVideoCapturer.m
@@ -27,22 +27,26 @@ static inline BOOL IsMediaSubTypeSupported(FourCharCode mediaSubType) {
 }
 
 @interface RTCCameraVideoCapturer ()<AVCaptureVideoDataOutputSampleBufferDelegate>
-@property(nonatomic, readonly) dispatch_queue_t frameQueue;
+@property(nonatomic, strong) AVCaptureVideoDataOutput *videoDataOutput;
+@property(nonatomic, strong) AVCaptureDevice *currentDevice;
+@property(nonatomic, strong) dispatch_queue_t frameQueue;
+@property(nonatomic, assign) RTCVideoRotation rotation;
+// Will the session be running once all asynchronous operations have been completed?
+@property(nonatomic, assign) BOOL willBeRunning;
+
 @end
 
 @implementation RTCCameraVideoCapturer {
-  AVCaptureVideoDataOutput *_videoDataOutput;
-  AVCaptureSession *_captureSession;
-  AVCaptureDevice *_currentDevice;
-  RTCVideoRotation _rotation;
   BOOL _hasRetriedOnFatalError;
   BOOL _isRunning;
-  // Will the session be running once all asynchronous operations have been completed?
-  BOOL _willBeRunning;
 }
 
-@synthesize frameQueue = _frameQueue;
 @synthesize captureSession = _captureSession;
+@synthesize currentDevice = _currentDevice;
+@synthesize frameQueue = _frameQueue;
+@synthesize rotation = _rotation;
+@synthesize videoDataOutput = _videoDataOutput;
+@synthesize willBeRunning = _willBeRunning;
 
 - (instancetype)initWithDelegate:(__weak id<RTCVideoCapturerDelegate>)delegate {
   if (self = [super initWithDelegate:delegate]) {
@@ -121,28 +125,10 @@ static inline BOOL IsMediaSubTypeSupported(FourCharCode mediaSubType) {
       dispatchAsyncOnType:RTCDispatcherTypeCaptureSession
                     block:^{
                       RTCLogInfo("startCaptureWithDevice %@ @ %d fps", format, fps);
-
 #if TARGET_OS_IPHONE
                       [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
 #endif
-
-                      _currentDevice = device;
-
-                      NSError *error = nil;
-                      if ([_currentDevice lockForConfiguration:&error]) {
-                        [self updateDeviceCaptureFormat:format fps:fps];
-                      } else {
-                        RTCLogError(@"Failed to lock device %@. Error: %@", _currentDevice,
-                                    error.userInfo);
-                        return;
-                      }
-
-                      [self reconfigureCaptureSessionInput];
-                      [self updateOrientation];
-                      [_captureSession startRunning];
-
-                      [_currentDevice unlockForConfiguration];
-                      _isRunning = true;
+                      _isRunning = [self tryStartCaptureWithDevice:device format:format fps:fps];
                     }];
 }
 
@@ -360,6 +346,27 @@ static inline BOOL IsMediaSubTypeSupported(FourCharCode mediaSubType) {
 
 #pragma mark - Private, called inside capture queue
 
+- (BOOL)tryStartCaptureWithDevice:(AVCaptureDevice *)device
+                           format:(AVCaptureDeviceFormat *)format
+                              fps:(int)fps {
+  _currentDevice = device;
+
+  NSError *error = nil;
+  if ([_currentDevice lockForConfiguration:&error]) {
+    [self updateDeviceCaptureFormat:format fps:fps];
+  } else {
+    RTCLogError(@"Failed to lock device %@. Error: %@", _currentDevice, error.userInfo);
+    return NO;
+  }
+
+  [self reconfigureCaptureSessionInput];
+  [self updateOrientation];
+  [_captureSession startRunning];
+
+  [_currentDevice unlockForConfiguration];
+  return YES;
+}
+
 - (void)updateDeviceCaptureFormat:(AVCaptureDeviceFormat *)format fps:(int)fps {
   @try {
     _currentDevice.activeFormat = format;
@@ -392,8 +399,14 @@ static inline BOOL IsMediaSubTypeSupported(FourCharCode mediaSubType) {
 
 - (void)updateOrientation {
 #if TARGET_OS_IPHONE
+  [self updateOrientation:[UIDevice currentDevice].orientation];
+#endif
+}
+
+#if TARGET_OS_IPHONE
+- (void)updateOrientation:(UIDeviceOrientation)orientation {
   BOOL usingFrontCamera = _currentDevice.position == AVCaptureDevicePositionFront;
-  switch ([UIDevice currentDevice].orientation) {
+  switch (orientation) {
     case UIDeviceOrientationPortrait:
       _rotation = RTCVideoRotation_90;
       break;
@@ -412,7 +425,7 @@ static inline BOOL IsMediaSubTypeSupported(FourCharCode mediaSubType) {
       // Ignore.
       break;
   }
-#endif
 }
+#endif
 
 @end