[Telemetry] Set youtube system health benchmarks to have platform specific recordings.

tools/perf/page_sets/data/system_health_desktop.json

Index: tools/perf/page_sets/data/system_health_desktop.json
diff --git a/tools/perf/page_sets/data/system_health_desktop.json b/tools/perf/page_sets/data/system_health_desktop.json
index c4a23e626545ac07d068602af6a004bdd7453699..bdbba9e2040139cf9b89b1f78a92cbf79a2a5f8b 100644
--- a/tools/perf/page_sets/data/system_health_desktop.json
+++ b/tools/perf/page_sets/data/system_health_desktop.json
@@ -10,7 +10,8 @@
             "DEFAULT": "system_health_desktop_036.wpr"
         },
         "browse:media:youtube": {
-            "DEFAULT": "system_health_desktop_026.wpr"
+            "DEFAULT": "system_health_desktop_026.wpr",
+            "linux": "system_health_desktop_026.wpr"
         },
         "browse:news:cnn": {
             "DEFAULT": "system_health_desktop_013.wpr"
@@ -70,7 +71,8 @@
             "DEFAULT": "system_health_desktop_003.wpr"
         },
         "load:media:youtube": {
-            "DEFAULT": "system_health_desktop_003.wpr"
+            "DEFAULT": "system_health_desktop_003.wpr",
+            "linux": "system_health_desktop_003.wpr"
         },
         "load:news:bbc": {
             "DEFAULT": "system_health_desktop_002.wpr"
@@ -180,4 +182,4 @@
     },
     "description": "Describes the Web Page Replay archives for a story set. Don't edit by hand! Use record_wpr for updating.",
     "platform_specific": true
-}
+}