[Telemetry] Create loading.desktop, a desktop analog for loading.mobile

tools/perf/benchmark.csv

Index: tools/perf/benchmark.csv
diff --git a/tools/perf/benchmark.csv b/tools/perf/benchmark.csv
index 8ee02ec47c57210affb724854ad5ed304fa7291d..8d9461cbca1de085a13cb7f6e6b4b32d340603c3 100644
--- a/tools/perf/benchmark.csv
+++ b/tools/perf/benchmark.csv
@@ -49,15 +49,16 @@ jitter,jaydasika@chromium.org,
 kraken,"bmeurer@chromium.org, mvstanton@chromium.org",
 load_library_perf_tests,,
 loading.cluster_telemetry,,
+loading.desktop,"kouhei@chormium.org, ksakamoto@chromium.org",
 loading.mobile,"kouhei@chromium.org, ksakamoto@chromium.org",
-media.android.tough_video_cases,,
+media.android.tough_video_cases,"crouleau@chromium.org, videostack-eng@google.com",Internals>Media
 media.android.tough_video_cases_tbmv2,"johnchen@chromium.org, crouleau@chromium.org",Internals>Media
-media.chromeOS.tough_video_cases,,
-media.chromeOS4kOnly.tough_video_cases,,
-media.media_cns_cases,"crouleau@chromium.org, videostack-eng@google.com",
-media.mse_cases,"crouleau@chromium.org, videostack-eng@google.com",
-media.tough_video_cases,,
-media.tough_video_cases_extra,"crouleau@chromium.org, videostack-eng@google.com",
+media.chromeOS.tough_video_cases,crouleau@chromium.org,Internals>Media
+media.chromeOS4kOnly.tough_video_cases,crouleau@chromium.org,Internals>Media
+media.media_cns_cases,"crouleau@chromium.org, videostack-eng@google.com",Internals>Media
+media.mse_cases,"crouleau@chromium.org, videostack-eng@google.com",Internals>Media>Source
+media.tough_video_cases,crouleau@chromium.org,Internals>Media
+media.tough_video_cases_extra,"crouleau@chromium.org, videostack-eng@google.com",Internals>Media
 media.tough_video_cases_tbmv2,"johnchen@chromium.org, crouleau@chromium.org",Internals>Media
 media_perftests,crouleau@chromium.org,
 memory.blink_memory_mobile,bashi@chromium.org,