Move CoreVideoFrameBuffer from webrtc/common_video/ to webrtc/sdk/objc/

webrtc/common_video/BUILD.gn

Index: webrtc/common_video/BUILD.gn
diff --git a/webrtc/common_video/BUILD.gn b/webrtc/common_video/BUILD.gn
index 6b7eb014002a9921a326ed6ebf68246d2e188477..d6005d0195b0ad2132fd4e83fa601dc577b7a2bb 100644
--- a/webrtc/common_video/BUILD.gn
+++ b/webrtc/common_video/BUILD.gn
@@ -73,14 +73,6 @@ rtc_static_library("common_video") {
     # Need to add a directory normally exported by libyuv.
     include_dirs += [ "$rtc_libyuv_dir/include" ]
   }
-
-  if (is_ios || is_mac) {
-    sources += [
-      "corevideo_frame_buffer.cc",
-      "include/corevideo_frame_buffer.h",
-    ]
-    libs = [ "CoreVideo.framework" ]
-  }
 }
 
 if (rtc_include_tests) {