Address tkchin's comments on RTCCameraVideoCapturer.

BUG=webrtc:7177

Review-Url: https://codereview.webrtc.org/2800853006
Cr-Commit-Position: refs/heads/master@{#17986}

webrtc/sdk/objc/Framework/Headers/WebRTC/RTCCameraVideoCapturer.h

@@ -20,6 +20,9 @@ RTC_EXPORT
 // (usually RTCVideoSource).
 @interface RTCCameraVideoCapturer : RTCVideoCapturer
 
+// Capture session that is used for capturing. Valid from initialization to dealloc.
+@property(readonly, nonatomic) AVCaptureSession *captureSession;
+
 // Returns list of available capture devices that support video capture.
 + (NSArray<AVCaptureDevice *> *)captureDevices;
 // Returns list of formats that are supported by this class for this device.
@@ -32,9 +35,6 @@ RTC_EXPORT
 // Stops the capture session asynchronously.
 - (void)stopCapture;
 
-// Capture session that is used for capturing. Valid from initialization to dealloc.
-@property(readonly, nonatomic) AVCaptureSession *captureSession;
-
 @end
 
 NS_ASSUME_NONNULL_END

webrtc/sdk/objc/Framework/Headers/WebRTC/RTCDispatcher.h

@@ -37,4 +37,9 @@ RTC_EXPORT
 + (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