Add one extra UMA for video casting

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 6139f203e917e5443e7594f56203928cfc0bbc9a..051be23a8dc1a94a18e9740d89d88072477fca8d 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -1343,6 +1343,10 @@ other types of suffix sets.
   </summary>
 </histogram>
 
+<histogram name="Cast.Sender.CastMediaType" enum="MediaContainers">
+  <summary>Records the media type of every video being cast.</summary>
+</histogram>
+
 <histogram name="Cast.Sender.CastPlaySuccess" enum="BooleanSuccess">
   <summary>
     Records the result of a request to play remotely. The value will be true if
@@ -27718,6 +27722,8 @@ other types of suffix sets.
   <int value="35" label="WAV / WAVE (Waveform Audio)"/>
   <int value="36" label="Matroska / WebM"/>
   <int value="37" label="WTV (Windows Television)"/>
+  <int value="38" label="DASH"/>
+  <int value="39" label="SmoothStream"/>
 </enum>
 
 <enum name="MediaGalleriesUsageType" type="int">