MacOS: Add metal renderer and view.

webrtc/sdk/BUILD.gn

 # 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("../webrtc.gni")
 if (is_ios) {
@@ skipping 192 matching lines @@
       libs = [
         "CoreGraphics.framework",
         "GLKit.framework",
         "OpenGLES.framework",
         "QuartzCore.framework",
       ]
     }
 
     if (is_mac) {
       sources += [
+        "objc/Framework/Classes/Metal/RTCMTLI420Renderer.h",
+        "objc/Framework/Classes/Metal/RTCMTLI420Renderer.mm",
+        "objc/Framework/Classes/Metal/RTCMTLNSVideoView.m",
         "objc/Framework/Classes/RTCNSGLVideoView.m",
+        "objc/Framework/Headers/WebRTC/RTCMTLNSVideoView.h",
         "objc/Framework/Headers/WebRTC/RTCNSGLVideoView.h",
       ]
       libs = [
+        "CoreVideo.framework",
         "CoreMedia.framework",
         "OpenGL.framework",
+        "Metal.framework",
+        "MetalKit.framework",
       ]
     }
 
     configs += [
       "..:common_objc",
       "//build/config/compiler:enable_arc",
     ]
 
     public_configs = [ ":rtc_sdk_common_objc_config" ]
 
@@ skipping 190 matching lines @@
       deps += [ "$rtc_libyuv_dir" ]
       public_deps = [
         "$rtc_libyuv_dir",
       ]
     } else {
       # Need to add a directory normally exported by libyuv.
       include_dirs = [ "$rtc_libyuv_dir/include" ]
     }
   }
 }