Bug 1620669 - Separate CONTAINS_REMOTE_SUBFRAMES to its own label in BFCACHE_COMBO telemetry r=nika

Differential Revision: https://phabricator.services.mozilla.com/D65792

--HG--
extra : moz-landing-system : lando

docshell/base/nsDocShell.cpp

@@ -6770,6 +6770,10 @@ void nsDocShell::ReportBFCacheComboTelemetry(uint16_t aCombo) {
       Telemetry::AccumulateCategorical(
           Telemetry::LABELS_BFCACHE_COMBO::SPD_Unload_Req_Peer);
       break;
+    case REMOTE_SUBFRAMES:
+      Telemetry::AccumulateCategorical(
+          Telemetry::LABELS_BFCACHE_COMBO::Remote_Subframes);
+      break;
     default:
       Telemetry::AccumulateCategorical(Telemetry::LABELS_BFCACHE_COMBO::Other);
       break;

docshell/base/nsDocShell.h

@@ -907,6 +907,7 @@ class nsDocShell final : public nsDocLoader,
         mozilla::dom::BFCacheStatus::UNLOAD_LISTENER |
         mozilla::dom::BFCacheStatus::REQUEST |
         mozilla::dom::BFCacheStatus::ACTIVE_PEER_CONNECTION,
+    REMOTE_SUBFRAMES = mozilla::dom::BFCacheStatus::CONTAINS_REMOTE_SUBFRAMES
   };
 
   void ReportBFCacheComboTelemetry(uint16_t aCombo);

toolkit/components/telemetry/Histograms.json

@@ -14535,6 +14535,7 @@
       "Unload_Req_Peer_MSE",
       "Unload_Req_MSE",
       "SPD_Unload_Req_Peer",
+      "Remote_Subframes",
       "Other"
     ],
     "description": "The common combinations of BFCacheStatus when we determine whether the page can be BFCached or not; If it's BFCached, we record BFCache_Success; Success_Not_Toplevel represents the number of not the only top level document in BrowsingContextGroup's documents that are BFCached, and BFCache_Success includes Success_Not_Toplevel; If it's not and it falls under common failure reasons combinations, we record the corresponding combination; Otherwise, we record Other to indicate this is not a common failure"