Move MediaConstraintsInterface to sdk/, and make it a concrete class

Bug: webrtc:9239
Change-Id: I545ebf59b078dd94bc466886616dd374e4b2e226
Reviewed-on: https://webrtc-review.googlesource.com/c/122502
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26682}
diff --git a/sdk/objc/api/peerconnection/RTCMediaConstraints+Private.h b/sdk/objc/api/peerconnection/RTCMediaConstraints+Private.h
index 335b029..b3e1b10 100644
--- a/sdk/objc/api/peerconnection/RTCMediaConstraints+Private.h
+++ b/sdk/objc/api/peerconnection/RTCMediaConstraints+Private.h
@@ -12,25 +12,7 @@
 
 #include <memory>
 
-#include "api/media_constraints_interface.h"
-
-namespace webrtc {
-
-class MediaConstraints : public MediaConstraintsInterface {
- public:
-  ~MediaConstraints() override;
-  MediaConstraints();
-  MediaConstraints(const MediaConstraintsInterface::Constraints& mandatory,
-                   const MediaConstraintsInterface::Constraints& optional);
-  const Constraints& GetMandatory() const override;
-  const Constraints& GetOptional() const override;
-
- private:
-  MediaConstraintsInterface::Constraints mandatory_;
-  MediaConstraintsInterface::Constraints optional_;
-};
-
-}  // namespace webrtc
+#include "sdk/media_constraints.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -43,8 +25,8 @@
 - (std::unique_ptr<webrtc::MediaConstraints>)nativeConstraints;
 
 /** Return a native Constraints object representing these constraints */
-+ (webrtc::MediaConstraintsInterface::Constraints)nativeConstraintsForConstraints:
-        (NSDictionary<NSString*, NSString*>*)constraints;
++ (webrtc::MediaConstraints::Constraints)nativeConstraintsForConstraints:
+    (NSDictionary<NSString*, NSString*>*)constraints;
 
 @end