Move Objective-C video renderers to webrtc/api/objc.

webrtc/api/objc/RTCNSGLVideoView.h

Index: webrtc/api/objc/RTCNSGLVideoView.h
diff --git a/webrtc/base/objc/NSString+StdString.h b/webrtc/api/objc/RTCNSGLVideoView.h
similarity index 54%
copy from webrtc/base/objc/NSString+StdString.h
copy to webrtc/api/objc/RTCNSGLVideoView.h
index 532032b3fca66977290d612f1e998c205cceef00..27eb31e9af12a72c8fefccfd89cc6cc5d2ea2f89 100644
--- a/webrtc/base/objc/NSString+StdString.h
+++ b/webrtc/api/objc/RTCNSGLVideoView.h
@@ -8,17 +8,26 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#import <Foundation/Foundation.h>
+#if TARGET_OS_IPHONE
+#error "This file targets OSX."
+#endif
 
-#include <string>
+#import <AppKit/NSOpenGLView.h>
+
+#import "RTCVideoRenderer.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
-@interface NSString (StdString)
+@class RTCNSGLVideoView;
+@protocol RTCNSGLVideoViewDelegate
+
+- (void)videoView:(RTCNSGLVideoView *)videoView didChangeVideoSize:(CGSize)size;
+
+@end
 
-@property(nonatomic, readonly) std::string stdString;
+@interface RTCNSGLVideoView : NSOpenGLView <RTCVideoRenderer>
 
-+ (std::string)stdStringForString:(NSString *)nsString;
+@property(nonatomic, weak) id<RTCNSGLVideoViewDelegate> delegate;
 
 @end