iOS: Add support for rendering native CVPixelBuffers directly

webrtc/sdk/objc/Framework/Classes/RTCShader.h

Index: webrtc/sdk/objc/Framework/Classes/RTCShader.h
diff --git a/webrtc/sdk/objc/Framework/Classes/RTCShader.h b/webrtc/sdk/objc/Framework/Classes/RTCShader.h
new file mode 100644
index 0000000000000000000000000000000000000000..ac2d0f6ee00e6b3b33729f8668d935d12ff91671
--- /dev/null
+++ b/webrtc/sdk/objc/Framework/Classes/RTCShader.h
@@ -0,0 +1,43 @@
+/*
+ *  Copyright 2016 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 "RTCOpenGLDefines.h"
+
+@class RTCVideoFrame;
+
+@protocol RTCShader <NSObject>
+
+- (BOOL)drawFrame:(RTCVideoFrame *)frame;
+
+@end
+
+// Shader for non-native I420 frames.
+@interface RTCI420Shader : NSObject <RTCShader>
+
+- (instancetype)init NS_UNAVAILABLE;
+- (instancetype)initWithContext:(GlContextType *)context NS_DESIGNATED_INITIALIZER;
+- (BOOL)drawFrame:(RTCVideoFrame *)frame;
+
+@end
+
+// Native CVPixelBufferRef rendering is only supported on iPhone because it
+// depends on CVOpenGLESTextureCacheCreate.
+#if TARGET_OS_IPHONE
+
+// Shader for native NV12 frames.
+@interface RTCNativeNV12Shader : NSObject <RTCShader>
+
+- (instancetype)init NS_UNAVAILABLE;
+- (instancetype)initWithContext:(GlContextType *)context NS_DESIGNATED_INITIALIZER;
+- (BOOL)drawFrame:(RTCVideoFrame *)frame;
+
+@end
+
+#endif  // TARGET_OS_IPHONE