--- a/toolkit/components/telemetry/TelemetryEnvironment.jsm
+++ b/toolkit/components/telemetry/TelemetryEnvironment.jsm
@@ -268,16 +268,17 @@ const PREF_DISTRIBUTOR = "app.distributo
 const PREF_DISTRIBUTOR_CHANNEL = "app.distributor.channel";
 const PREF_HOTFIX_LASTVERSION = "extensions.hotfix.lastVersion";
 const PREF_APP_PARTNER_BRANCH = "app.partner.";
 const PREF_PARTNER_ID = "mozilla.partner.id";
 const PREF_UPDATE_ENABLED = "app.update.enabled";
 const PREF_UPDATE_AUTODOWNLOAD = "app.update.auto";
 const PREF_SEARCH_COHORT = "browser.search.cohort";
 const PREF_E10S_COHORT = "e10s.rollout.cohort";
+const PREF_SEARCH_INNAVBAR = "browser.search.widget.inNavBar";
 
 const COMPOSITOR_CREATED_TOPIC = "compositor:created";
 const COMPOSITOR_PROCESS_ABORTED_TOPIC = "compositor:process-aborted";
 const DISTRIBUTION_CUSTOMIZATION_COMPLETE_TOPIC = "distribution-customization-complete";
 const EXPERIMENTS_CHANGED_TOPIC = "experiments-changed";
 const GFX_FEATURES_READY_TOPIC = "gfx-features-ready";
 const SEARCH_ENGINE_MODIFIED_TOPIC = "browser-search-engine-modified";
 const SEARCH_SERVICE_TOPIC = "browser-search-service";
@@ -1379,16 +1380,17 @@ EnvironmentCache.prototype = {
       locale: getBrowserLocale(),
       update: {
         channel: updateChannel,
         enabled: Services.prefs.getBoolPref(PREF_UPDATE_ENABLED, true),
         autoDownload: Services.prefs.getBoolPref(PREF_UPDATE_AUTODOWNLOAD, true),
       },
       userPrefs: this._getPrefData(),
       sandbox: this._getSandboxData(),
+      searchInNavbar: Services.prefs.getBoolPref(PREF_SEARCH_INNAVBAR, false),
     };
 
     this._currentEnvironment.settings.addonCompatibilityCheckEnabled =
       AddonManager.checkCompatibility;
 
     this._updateDefaultBrowser();
     this._updateSearchEngine();
   },

--- a/toolkit/components/telemetry/docs/data/environment.rst
+++ b/toolkit/components/telemetry/docs/data/environment.rst
@@ -66,17 +66,18 @@ Structure:
           // all of these values are optional.
           source: <string>, // referring partner domain, when install happens via a known partner
           medium: <string>, // category of the source, such as "organic" for a search engine
           campaign: <string>, // identifier of the particular campaign that led to the download of the product
           content: <string>, // identifier to indicate the particular link within a campaign
         },
         sandbox: {
           effectiveContentProcessLevel: <integer>,
-        }
+        },
+        searchInNavbar: <bool> // false if the unified searchbar is used, false if 2 bars
       },
       profile: {
         creationDate: <integer>, // integer days since UNIX epoch, e.g. 16446
         resetDate: <integer>, // integer days since UNIX epoch, e.g. 16446 - optional
       },
       partner: { // This section may not be immediately available on startup
         distributionId: <string>, // pref "distribution.id", null on failure
         distributionVersion: <string>, // pref "distribution.version", null on failure