[Cast] Compute utilization metrics and add performance overlay.

media/cast/BUILD.gn

Index: media/cast/BUILD.gn
diff --git a/media/cast/BUILD.gn b/media/cast/BUILD.gn
index b6df09f4e874838ae7bbf76433b65d26749229be..48c3bc3bd32f785ff020d628d58f09e34254624e 100644
--- a/media/cast/BUILD.gn
+++ b/media/cast/BUILD.gn
@@ -121,6 +121,10 @@ source_set("sender") {
     "sender/fake_software_video_encoder.h",
     "sender/frame_sender.cc",
     "sender/frame_sender.h",
+    "sender/performance_metrics_overlay.cc",
+    "sender/performance_metrics_overlay.h",
+    "sender/sender_encoded_frame.cc",
+    "sender/sender_encoded_frame.h",
     "sender/size_adaptable_video_encoder_base.cc",
     "sender/size_adaptable_video_encoder_base.h",
     "sender/software_video_encoder.h",
@@ -172,16 +176,12 @@ source_set("sender") {
       "sender/h264_vt_encoder.h",
     ]
 
-    libs += [
-      "CoreVideo.framework",
-    ]
+    libs += [ "CoreVideo.framework" ]
   }
 
   if (is_mac) {
     # Required by audio_encoder.cc.
-    libs += [
-      "AudioToolbox.framework",
-    ]
+    libs += [ "AudioToolbox.framework" ]
   }
 }