Add metal view, shaders and renderer.

webrtc/sdk/objc/Framework/Classes/metal/RTCNV12Renderer.h

Index: webrtc/sdk/objc/Framework/Classes/metal/RTCNV12Renderer.h
diff --git a/webrtc/sdk/objc/Framework/Classes/metal/RTCNV12Renderer.h b/webrtc/sdk/objc/Framework/Classes/metal/RTCNV12Renderer.h
new file mode 100644
index 0000000000000000000000000000000000000000..aff7f991cfd71673c4f42ae0282e9a0f7f6707e2
--- /dev/null
+++ b/webrtc/sdk/objc/Framework/Classes/metal/RTCNV12Renderer.h
@@ -0,0 +1,18 @@
+/*
+ *  Copyright 2017 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 <Foundation/Foundation.h>

[tkchin_webrtc, 2017/02/10 23:32:10]

nit: newline after system imports

[daniela-webrtc, 2017/02/13 12:32:06]

Done.

+#import "WebRTC/RTCMTLRenderer.h"
+
+/**
+ * Implementation of RTCMTLRenderer protocol for rendering native nv12 video frames.

[tkchin_webrtc, 2017/02/10 23:32:09]

nit: place after **
/** Imple..

[daniela-webrtc, 2017/02/13 12:32:06]

Done.

+ */
+@interface RTCNV12Renderer : NSObject<RTCMTLRenderer>

[tkchin_webrtc, 2017/02/10 23:32:10]

Should this be RTCNV12MetalRenderer?

Do we have plans to compare Metal vs OpenGL perf?

[tkchin_webrtc, 2017/02/10 23:32:10]

nit: NSObject <

[daniela-webrtc, 2017/02/13 12:32:06]

According to the guidelines (and the Clang formatter that I use locally) there
should be no space.
https://google.github.io/styleguide/objcguide.xml?showone=Protocols#Protocols

[tkchin_webrtc, 2017/02/14 00:23:54]

See internal style guide (rev. 3.85). There isn't official guidance here, so we
should stay consistent with our own rep and use a space. Personally I recommend
following style of core Google components.

+@end