Update API for Objective-C RTCMediaConstraints.

webrtc/api/objc/RTCMediaConstraints+Private.h

+/*
+ *  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 "RTCMediaConstraints.h"
+
+#include "talk/app/webrtc/mediaconstraintsinterface.h"
+#include "webrtc/base/scoped_ptr.h"
+
+namespace webrtc {
+
+class MediaConstraints : public MediaConstraintsInterface {
+ public:
+  virtual ~MediaConstraints();
+  MediaConstraints();
+  MediaConstraints(
+      const MediaConstraintsInterface::Constraints& mandatory,
+      const MediaConstraintsInterface::Constraints& optional);
+  virtual const Constraints& GetMandatory() const;
+  virtual const Constraints& GetOptional() const;
+
+ private:
+  MediaConstraintsInterface::Constraints mandatory_;
+  MediaConstraintsInterface::Constraints optional_;
+};
+
+}  // namespace webrtc
+
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface RTCMediaConstraints ()
+
+/**
+ * A MediaConstraints representation of this RTCMediaConstraints object. This is
+ * needed to pass to the underlying C++ APIs.
+ */
+- (rtc::scoped_ptr<webrtc::MediaConstraints>)nativeConstraints;
+
+/** Return a native Constraints object representing these constraints */
++ (webrtc::MediaConstraintsInterface::Constraints)
+    nativeConstraintsForConstraints:
+        (NSDictionary<NSString *, NSString *> *)constraints;
+
+@end
+
+NS_ASSUME_NONNULL_END