[MediaRouter] Record DIAL device counts in DialMediaSinkServiceImpl

chrome/browser/media/router/media_router_metrics_unittest.cc

Index: chrome/browser/media/router/media_router_metrics_unittest.cc
diff --git a/chrome/browser/media/router/media_router_metrics_unittest.cc b/chrome/browser/media/router/media_router_metrics_unittest.cc
index be1a5a9356de3a8424ce5bb9fd45d3dce850fb92..57d6c0597dd627eb6409616f0228ac71e59878db 100644
--- a/chrome/browser/media/router/media_router_metrics_unittest.cc
+++ b/chrome/browser/media/router/media_router_metrics_unittest.cc
@@ -93,4 +93,19 @@ TEST(MediaRouterMetricsTest, RecordRouteCreationOutcome) {
                   Bucket(static_cast<int>(outcome2), 2)));
 }
 
+TEST(MediaRouterMetricsTest, RecordDialDeviceCounts) {
+  base::HistogramTester tester;
+  tester.ExpectTotalCount(MediaRouterMetrics::kDialAvailableDeviceCount, 0);
+  tester.ExpectTotalCount(MediaRouterMetrics::kDialKnownDeviceCount, 0);
+
+  MediaRouterMetrics::RecordDialDeviceCounts(6, 10);
+  MediaRouterMetrics::RecordDialDeviceCounts(7, 10);
+
+  tester.ExpectTotalCount(MediaRouterMetrics::kDialAvailableDeviceCount, 2);
+  tester.ExpectTotalCount(MediaRouterMetrics::kDialKnownDeviceCount, 2);
+  tester.ExpectBucketCount(MediaRouterMetrics::kDialAvailableDeviceCount, 6, 1);
+  tester.ExpectBucketCount(MediaRouterMetrics::kDialAvailableDeviceCount, 7, 1);
+  tester.ExpectBucketCount(MediaRouterMetrics::kDialKnownDeviceCount, 10, 2);
+}
+
 }  // namespace media_router