Update API for Objective-C RTCSessionDescription.

webrtc/api/objc/RTCSessionDescription+Private.h

Index: webrtc/api/objc/RTCSessionDescription+Private.h
diff --git a/webrtc/api/objc/RTCSessionDescription+Private.h b/webrtc/api/objc/RTCSessionDescription+Private.h
new file mode 100644
index 0000000000000000000000000000000000000000..aa0314d3f3fcd27291fe25f532bbc041fee77f9f
--- /dev/null
+++ b/webrtc/api/objc/RTCSessionDescription+Private.h
@@ -0,0 +1,41 @@
+/*
+ *  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 "RTCSessionDescription.h"
+
+#include "talk/app/webrtc/jsep.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface RTCSessionDescription ()
+
+/**
+ * The native SessionDescriptionInterface representation of this
+ * RTCSessionDescription object. This is needed to pass to the underlying C++
+ * APIs.
+ */
+@property(nonatomic, readonly)
+    webrtc::SessionDescriptionInterface *nativeDescription;
+
+/**
+ * Initialize an RTCSessionDescription from a native
+ * SessionDescriptionInterface. No ownership is taken of the native session
+ * description.
+ */
+- (instancetype)initWithNativeDescription:
+    (webrtc::SessionDescriptionInterface *)nativeDescription;
+
++ (std::string)stringForType:(RTCSdpType)type;
+
++ (RTCSdpType)typeForString:(const std::string &)string;
+
+@end
+
+NS_ASSUME_NONNULL_END