Add ifdef protection for iOS-only headers

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

Index: webrtc/sdk/objc/Framework/Headers/WebRTC/WebRTC.h
diff --git a/webrtc/sdk/objc/Framework/Headers/WebRTC/WebRTC.h b/webrtc/sdk/objc/Framework/Headers/WebRTC/WebRTC.h
index 8082d02afd309b74fbce2b92423f0bf5c8e6daef..27fad0df3131c85878d4bdb1935936dc7757bf6f 100644
--- a/webrtc/sdk/objc/Framework/Headers/WebRTC/WebRTC.h
+++ b/webrtc/sdk/objc/Framework/Headers/WebRTC/WebRTC.h
@@ -11,12 +11,16 @@
 #import <WebRTC/RTCAVFoundationVideoSource.h>
 #import <WebRTC/RTCAudioSource.h>
 #import <WebRTC/RTCAudioTrack.h>
+#if TARGET_OS_IPHONE
 #import <WebRTC/RTCCameraPreviewView.h>
+#endif
 #import <WebRTC/RTCConfiguration.h>
 #import <WebRTC/RTCDataChannel.h>
 #import <WebRTC/RTCDataChannelConfiguration.h>
 #import <WebRTC/RTCDispatcher.h>
+#if TARGET_OS_IPHONE
 #import <WebRTC/RTCEAGLVideoView.h>
+#endif
 #import <WebRTC/RTCFieldTrials.h>
 #import <WebRTC/RTCFileLogger.h>
 #import <WebRTC/RTCIceCandidate.h>
@@ -44,4 +48,6 @@
 #import <WebRTC/RTCVideoRenderer.h>
 #import <WebRTC/RTCVideoSource.h>
 #import <WebRTC/RTCVideoTrack.h>
+#if TARGET_OS_IPHONE
 #import <WebRTC/UIDevice+RTCDevice.h>
+#endif