Bug 1884378 - Add Sandbox profiler category r=canaltinova,profiler-reviewers,aabh

Differential Revision: https://phabricator.services.mozilla.com/D207737

mozglue/baseprofiler/build/profiling_categories.yaml

@@ -305,3 +305,10 @@
   subcategories:
     - name: REMOTE_PROTOCOL
       label: Other
+
+- name: SANDBOX
+  label: Sandbox
+  color: grey
+  subcategories:
+    - name: SANDBOX
+      label: Other

tools/profiler/core/MicroGeckoProfiler.cpp

@@ -42,6 +42,8 @@ Maybe<MarkerTiming> ToTiming(char phase) {
 
 MarkerCategory ToCategory(const char category) {
   switch (category) {
+    case 'S':
+      return geckoprofiler::category::SANDBOX;
     case 'M':
       return geckoprofiler::category::MEDIA_RT;
     default: