Obj-C SDK Cleanup

This CL separates the files under sdk/objc into logical directories, replacing
the previous file layout under Framework/.

A long term goal is to have some system set up to generate the files under
sdk/objc/api (the PeerConnection API wrappers) from the C++ code. In the shorter
term the goal is to abstract out shared concepts from these classes in order to
make them as uniform as possible.

The separation into base/, components/, and helpers/ are to differentiate between
the base layer's common protocols, various utilities and the actual platform
specific components.

The old directory layout that resembled a framework's internal layout is not
necessary, since it is generated by the framework target when building it.

Bug: webrtc:9627
Change-Id: Ib084fd83f050ae980649ca99e841f4fb0580bd8f
Reviewed-on: https://webrtc-review.googlesource.com/94142
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
Reviewed-by: Henrik Andreassson <henrika@webrtc.org>
Commit-Queue: Anders Carlsson <andersc@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24493}

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

@@ -8,33 +8,4 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#import <Foundation/Foundation.h>
-#if TARGET_OS_IPHONE
-#import <UIKit/UIKit.h>
-#endif
-
-#import <WebRTC/RTCMacros.h>
-
-NS_ASSUME_NONNULL_BEGIN
-
-@class RTCVideoFrame;
-
-RTC_EXPORT
-@protocol RTCVideoRenderer <NSObject>
-
-/** The size of the frame. */
-- (void)setSize:(CGSize)size;
-
-/** The frame to be displayed. */
-- (void)renderFrame:(nullable RTCVideoFrame *)frame;
-
-@end
-
-RTC_EXPORT
-@protocol RTCVideoViewDelegate
-
-- (void)videoView:(id<RTCVideoRenderer>)videoView didChangeVideoSize:(CGSize)size;
-
-@end
-
-NS_ASSUME_NONNULL_END
+#import "base/RTCVideoRenderer.h"