Bug 1714112: Add new Fission decision value for phased rollout enablement. r=nika,fluent-reviewers,flod

This should be less confusing to users, and makes it easier to triage
about:support data.

Differential Revision: https://phabricator.services.mozilla.com/D118416

toolkit/content/aboutSupport.js

@@ -149,6 +149,7 @@ var snapshotFormatters = {
       enabledByUserPref: "fission-status-enabled-by-user-pref",
       disabledByUserPref: "fission-status-disabled-by-user-pref",
       disabledByE10sOther: "fission-status-disabled-by-e10s-other",
+      enabledByRollout: "fission-status-enabled-by-rollout",
     };
 
     let statusTextId = STATUS_STRINGS[data.fissionDecisionStatus];

toolkit/locales/en-US/toolkit/about/aboutSupport.ftl

@@ -378,6 +378,7 @@ fission-status-disabled-by-default = Disabled by default
 fission-status-enabled-by-user-pref = Enabled by user
 fission-status-disabled-by-user-pref = Disabled by user
 fission-status-disabled-by-e10s-other = E10s disabled
+fission-status-enabled-by-rollout = Enabled by phased rollout
 
 async-pan-zoom = Asynchronous Pan/Zoom
 apz-none = none

toolkit/xre/nsAppRunner.cpp

@@ -585,7 +585,8 @@ bool BrowserTabsRemoteAutostart() {
 bool FissionExperimentEnrolled() {
   MOZ_ASSERT(XRE_IsParentProcess());
   return gFissionExperimentStatus == nsIXULRuntime::eExperimentStatusControl ||
-         gFissionExperimentStatus == nsIXULRuntime::eExperimentStatusTreatment;
+         gFissionExperimentStatus == nsIXULRuntime::eExperimentStatusTreatment ||
+         gFissionExperimentStatus == nsIXULRuntime::eExperimentStatusRollout;
 }
 
 }  // namespace mozilla
@@ -683,7 +684,8 @@ static void EnsureFissionAutostartInitialized() {
   // enrollment status.
   if (FissionExperimentEnrolled()) {
     bool isTreatment =
-        gFissionExperimentStatus == nsIXULRuntime::eExperimentStatusTreatment;
+        gFissionExperimentStatus == nsIXULRuntime::eExperimentStatusTreatment ||
+        gFissionExperimentStatus == nsIXULRuntime::eExperimentStatusRollout;
     Preferences::SetBool(kPrefFissionAutostart, isTreatment,
                          PrefValueKind::Default);
   }
@@ -710,6 +712,9 @@ static void EnsureFissionAutostartInitialized() {
     } else if (gFissionExperimentStatus ==
                nsIXULRuntime::eExperimentStatusTreatment) {
       gFissionDecisionStatus = nsIXULRuntime::eFissionExperimentTreatment;
+    } else if (gFissionExperimentStatus ==
+               nsIXULRuntime::eExperimentStatusRollout) {
+      gFissionDecisionStatus = nsIXULRuntime::eFissionEnabledByRollout;
     } else if (Preferences::HasUserValue(kPrefFissionAutostart)) {
       gFissionDecisionStatus = gFissionAutostart
                                    ? nsIXULRuntime::eFissionEnabledByUserPref
@@ -1125,6 +1130,9 @@ nsXULAppInfo::GetFissionDecisionStatusString(nsACString& aResult) {
     case eFissionDisabledByE10sOther:
       aResult = "disabledByE10sOther";
       break;
+    case eFissionEnabledByRollout:
+      aResult = "enabledByRollout";
+      break;
     default:
       MOZ_ASSERT_UNREACHABLE("Unexpected enum value");
   }

xpcom/system/nsIXULRuntime.idl

@@ -66,6 +66,8 @@ interface nsIXULRuntime : nsISupports
     // The user was enrolled in the experiment, but became ineligible due to
     // manually modifying a relevant preference.
     eExperimentStatusDisqualified = 3,
+    // The user was selected for the phased Fission rollout.
+    eExperimentStatusRollout = 4,
 
     eExperimentStatusCount,
   };
@@ -103,6 +105,8 @@ interface nsIXULRuntime : nsISupports
     eFissionDisabledByUserPref = 9,
     // Fission is disabled because e10s is disabled for some other reason.
     eFissionDisabledByE10sOther = 10,
+    // Fission is enabled by a Normandy phased rollout.
+    eFissionEnabledByRollout = 11,
   };
 
   /**