--- a/mobile/android/base/java/org/mozilla/gecko/BrowserApp.java
+++ b/mobile/android/base/java/org/mozilla/gecko/BrowserApp.java
@@ -49,16 +49,17 @@ import org.mozilla.gecko.permissions.Per
 import org.mozilla.gecko.preferences.ClearOnShutdownPref;
 import org.mozilla.gecko.preferences.GeckoPreferences;
 import org.mozilla.gecko.prompts.Prompt;
 import org.mozilla.gecko.prompts.PromptListItem;
 import org.mozilla.gecko.reader.ReaderModeUtils;
 import org.mozilla.gecko.reader.ReadingListHelper;
 import org.mozilla.gecko.restrictions.Restrictable;
 import org.mozilla.gecko.restrictions.RestrictedProfileConfiguration;
+import org.mozilla.gecko.search.SearchEngineManager;
 import org.mozilla.gecko.sync.repositories.android.FennecTabsRepository;
 import org.mozilla.gecko.tabqueue.TabQueueHelper;
 import org.mozilla.gecko.tabqueue.TabQueuePrompt;
 import org.mozilla.gecko.tabs.TabHistoryController;
 import org.mozilla.gecko.tabs.TabHistoryController.OnShowTabHistory;
 import org.mozilla.gecko.tabs.TabHistoryFragment;
 import org.mozilla.gecko.tabs.TabHistoryPage;
 import org.mozilla.gecko.tabs.TabsPanel;
@@ -146,16 +147,17 @@ import android.animation.Animator;
 import android.animation.ObjectAnimator;
 import org.json.JSONException;
 import org.json.JSONObject;
 
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.lang.ref.WeakReference;
 import java.lang.reflect.Method;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLEncoder;
 import java.util.EnumSet;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
@@ -277,16 +279,18 @@ public class BrowserApp extends GeckoApp
     // (starting the animation), the HomePager is hidden, and the HomePager animation completes,
     // both the web content and the HomePager will be hidden. This flag is used to prevent the
     // race by determining if the web content should be hidden at the animation's end.
     private boolean mHideWebContentOnAnimationEnd;
 
     private final DynamicToolbar mDynamicToolbar = new DynamicToolbar();
     private final ScreenshotObserver mScreenshotObserver = new ScreenshotObserver();
 
+    private SearchEngineManager searchEngineManager;
+
     @Override
     public View onCreateView(final String name, final Context context, final AttributeSet attrs) {
         final View view;
         if (BrowserToolbar.class.getName().equals(name)) {
             view = BrowserToolbar.create(context, attrs);
         } else if (TabsPanel.TabsLayout.class.getName().equals(name)) {
             view = TabsPanel.createTabsLayout(context, attrs);
         } else {
@@ -687,17 +691,20 @@ public class BrowserApp extends GeckoApp
             "Menu:Add",
             "Menu:Remove",
             "Sanitize:ClearHistory",
             "Sanitize:ClearSyncedTabs",
             "Settings:Show",
             "Telemetry:Gather",
             "Updater:Launch");
 
+        // We want to upload the telemetry core ping as soon after startup as possible. It relies on the
+        // Distribution being initialized. If you move this initialization, ensure it plays well with telemetry.
         Distribution distribution = Distribution.init(this);
+        searchEngineManager = new SearchEngineManager(this, distribution);
 
         // Init suggested sites engine in BrowserDB.
         final SuggestedSites suggestedSites = new SuggestedSites(appContext, distribution);
         final BrowserDB db = getProfile().getDB();
         db.setSuggestedSites(suggestedSites);
 
         JavaAddonManager.getInstance().init(appContext);
         mSharedPreferencesHelper = new SharedPreferencesHelper(appContext);
@@ -1402,16 +1409,19 @@ public class BrowserApp extends GeckoApp
             mAccountsHelper.uninit();
             mAccountsHelper = null;
         }
 
         if (mZoomedView != null) {
             mZoomedView.destroy();
         }
 
+        searchEngineManager.destroy();
+        searchEngineManager = null;
+
         EventDispatcher.getInstance().unregisterGeckoThreadListener((GeckoEventListener) this,
             "Gecko:DelayedStartup",
             "Menu:Open",
             "Menu:Update",
             "LightweightTheme:Update",
             "Search:Keyword",
             "Prompt:ShowTop");
 
@@ -3945,23 +3955,48 @@ public class BrowserApp extends GeckoApp
         }
 
         final SharedPreferences sharedPrefs = GeckoSharedPrefs.forProfileName(this, profile.getName());
         final int seq = sharedPrefs.getInt(TelemetryConstants.PREF_SEQ_COUNT, 1);
 
         // We store synchronously before sending the Intent to ensure this sequence number will not be re-used.
         sharedPrefs.edit().putInt(TelemetryConstants.PREF_SEQ_COUNT, seq + 1).commit();
 
-        final Intent i = new Intent(TelemetryConstants.ACTION_UPLOAD_CORE);
-        i.setClass(this, TelemetryUploadService.class);
-        i.putExtra(TelemetryConstants.EXTRA_DOC_ID, UUID.randomUUID().toString());
-        i.putExtra(TelemetryConstants.EXTRA_PROFILE_NAME, profile.getName());
-        i.putExtra(TelemetryConstants.EXTRA_PROFILE_PATH, profile.getDir().toString());
-        i.putExtra(TelemetryConstants.EXTRA_SEQ, seq);
-        startService(i);
+        searchEngineManager.getEngine(new UploadTelemetryCallback(getContext(), seq, profile.getName(), profile.getDir()));
+    }
+
+    private static class UploadTelemetryCallback implements SearchEngineManager.SearchEngineCallback {
+        private final WeakReference<Context> contextWeakReference;
+        private final int seq;
+        private final String profileName;
+        private final String profileDirPath;
+
+        public UploadTelemetryCallback(final Context context, final int seq, final String profileName, final File profileDir) {
+            this.contextWeakReference = new WeakReference<>(context);
+            this.seq = seq;
+            this.profileName = profileName;
+            this.profileDirPath = profileDir.toString();
+        }
+
+        @Override
+        public void execute(final org.mozilla.gecko.search.SearchEngine engine) {
+            final Context context = this.contextWeakReference.get();
+            if (context == null) {
+                return;
+            }
+
+            final Intent i = new Intent(TelemetryConstants.ACTION_UPLOAD_CORE);
+            i.setClass(context, TelemetryUploadService.class);
+            i.putExtra(TelemetryConstants.EXTRA_DEFAULT_SEARCH_ENGINE, engine.getIdentifier());
+            i.putExtra(TelemetryConstants.EXTRA_DOC_ID, UUID.randomUUID().toString());
+            i.putExtra(TelemetryConstants.EXTRA_PROFILE_NAME, this.profileName);
+            i.putExtra(TelemetryConstants.EXTRA_PROFILE_PATH, this.profileDirPath);
+            i.putExtra(TelemetryConstants.EXTRA_SEQ, this.seq);
+            context.startService(i);
+        }
     }
 
     public static interface TabStripInterface {
         public void refresh();
         void setOnTabChangedListener(OnTabAddedOrRemovedListener listener);
         interface OnTabAddedOrRemovedListener {
             void onTabChanged();
         }

--- a/mobile/android/base/java/org/mozilla/gecko/telemetry/TelemetryConstants.java
+++ b/mobile/android/base/java/org/mozilla/gecko/telemetry/TelemetryConstants.java
@@ -11,33 +11,35 @@ public class TelemetryConstants {
     // Change these two values to enable upload in developer builds.
     public static final boolean UPLOAD_ENABLED = AppConstants.MOZILLA_OFFICIAL; // Disabled for developer builds.
     public static final String DEFAULT_SERVER_URL = "https://incoming.telemetry.mozilla.org";
 
     public static final String USER_AGENT =
             "Firefox-Android-Telemetry/" + AppConstants.MOZ_APP_VERSION + " (" + AppConstants.MOZ_APP_UA_NAME + ")";
 
     public static final String ACTION_UPLOAD_CORE = "uploadCore";
+    public static final String EXTRA_DEFAULT_SEARCH_ENGINE = "defaultSearchEngine";
     public static final String EXTRA_DOC_ID = "docId";
     public static final String EXTRA_PROFILE_NAME = "geckoProfileName";
     public static final String EXTRA_PROFILE_PATH = "geckoProfilePath";
     public static final String EXTRA_SEQ = "seq";
 
     public static final String PREF_SERVER_URL = "telemetry-serverUrl";
     public static final String PREF_SEQ_COUNT = "telemetry-seqCount";
 
     public static class CorePing {
         private CorePing() { /* To prevent instantiation */ }
 
         public static final String NAME = "core";
-        public static final int VERSION_VALUE = 1;
+        public static final int VERSION_VALUE = 2; // For version history, see toolkit/components/telemetry/docs/core-ping.rst
         public static final String OS_VALUE = "Android";
 
         public static final String ARCHITECTURE = "arch";
         public static final String CLIENT_ID = "clientId";
+        public static final String DEFAULT_SEARCH_ENGINE = "defaultSearch";
         public static final String DEVICE = "device";
         public static final String EXPERIMENTS = "experiments";
         public static final String LOCALE = "locale";
         public static final String OS_ATTR = "os";
         public static final String OS_VERSION = "osversion";
         public static final String PROFILE_CREATION_DATE = "profileDate";
         public static final String SEQ = "seq";
         public static final String VERSION_ATTR = "v";

--- a/mobile/android/base/java/org/mozilla/gecko/telemetry/TelemetryPingGenerator.java
+++ b/mobile/android/base/java/org/mozilla/gecko/telemetry/TelemetryPingGenerator.java
@@ -2,16 +2,18 @@
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 package org.mozilla.gecko.telemetry;
 
 import android.content.Context;
 import android.os.Build;
+import android.support.annotation.Nullable;
+import android.text.TextUtils;
 
 import org.mozilla.gecko.AppConstants;
 import org.mozilla.gecko.Locales;
 import org.mozilla.gecko.sync.ExtendedJSONObject;
 import org.mozilla.gecko.telemetry.TelemetryConstants.CorePing;
 import org.mozilla.gecko.util.Experiments;
 import org.mozilla.gecko.util.StringUtils;
 
@@ -57,36 +59,39 @@ public class TelemetryPingGenerator {
     /**
      * @param docId A unique document ID for the ping associated with the upload to this server
      * @param clientId The client ID of this profile (from Gecko)
      * @param serverURLSchemeHostPort The server url with the scheme, host, and port (e.g. "http://mozilla.org:80")
      * @param profileCreationDateDays The profile creation date in days to the UNIX epoch, NOT MILLIS.
      * @throws IOException when client ID could not be created
      */
     public static TelemetryPing createCorePing(final Context context, final String docId, final String clientId,
-            final String serverURLSchemeHostPort, final int seq, final long profileCreationDateDays) {
+            final String serverURLSchemeHostPort, final int seq, final long profileCreationDateDays,
+            @Nullable final String defaultSearchEngine) {
         final String serverURL = getTelemetryServerURL(docId, serverURLSchemeHostPort, CorePing.NAME);
-        final ExtendedJSONObject payload = createCorePingPayload(context, clientId, seq, profileCreationDateDays);
+        final ExtendedJSONObject payload =
+                createCorePingPayload(context, clientId, seq, profileCreationDateDays, defaultSearchEngine);
         return new TelemetryPing(serverURL, payload);
     }
 
     private static ExtendedJSONObject createCorePingPayload(final Context context, final String clientId,
-            final int seq, final long profileCreationDate) {
+            final int seq, final long profileCreationDate, @Nullable final String defaultSearchEngine) {
         final ExtendedJSONObject ping = new ExtendedJSONObject();
         ping.put(CorePing.VERSION_ATTR, CorePing.VERSION_VALUE);
         ping.put(CorePing.OS_ATTR, CorePing.OS_VALUE);
 
         // We limit the device descriptor to 32 characters because it can get long. We give fewer characters to the
         // manufacturer because we're less likely to have manufacturers with similar names than we are for a
         // manufacturer to have two devices with the similar names (e.g. Galaxy S6 vs. Galaxy Note 6).
         final String deviceDescriptor =
                 StringUtils.safeSubstring(Build.MANUFACTURER, 0, 12) + '-' + StringUtils.safeSubstring(Build.MODEL, 0, 19);
 
         ping.put(CorePing.ARCHITECTURE, AppConstants.ANDROID_CPU_ARCH);
         ping.put(CorePing.CLIENT_ID, clientId);
+        ping.put(CorePing.DEFAULT_SEARCH_ENGINE, TextUtils.isEmpty(defaultSearchEngine) ? null : defaultSearchEngine);
         ping.put(CorePing.DEVICE, deviceDescriptor);
         ping.put(CorePing.LOCALE, Locales.getLanguageTag(Locale.getDefault()));
         ping.put(CorePing.OS_VERSION, Integer.toString(Build.VERSION.SDK_INT)); // A String for cross-platform reasons.
         ping.put(CorePing.SEQ, seq);
         ping.putArray(CorePing.EXPERIMENTS, Experiments.getActiveExperiments(context));
         // TODO (bug 1246816): Remove this "optional" parameter work-around when
         // GeckoProfile.getAndPersistProfileCreationDateFromFilesystem is implemented. That method returns -1
         // while it's not implemented so we don't include the parameter in the ping if that's the case.

--- a/mobile/android/base/java/org/mozilla/gecko/telemetry/TelemetryUploadService.java
+++ b/mobile/android/base/java/org/mozilla/gecko/telemetry/TelemetryUploadService.java
@@ -3,16 +3,17 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 package org.mozilla.gecko.telemetry;
 
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.support.annotation.WorkerThread;
 import android.util.Log;
 import ch.boye.httpclientandroidlib.HttpResponse;
 import ch.boye.httpclientandroidlib.client.ClientProtocolException;
 import org.mozilla.gecko.GeckoProfile;
 import org.mozilla.gecko.GeckoSharedPrefs;
 import org.mozilla.gecko.background.BackgroundService;
 import org.mozilla.gecko.preferences.GeckoPreferences;
@@ -76,23 +77,24 @@ public class TelemetryUploadService exte
             return;
         }
 
         if (!TelemetryConstants.ACTION_UPLOAD_CORE.equals(intent.getAction())) {
             Log.w(LOGTAG, "Unknown action: " + intent.getAction() + ". Returning");
             return;
         }
 
+        final String defaultSearchEngine = intent.getStringExtra(TelemetryConstants.EXTRA_DEFAULT_SEARCH_ENGINE);
         final String docId = intent.getStringExtra(TelemetryConstants.EXTRA_DOC_ID);
         final int seq = intent.getIntExtra(TelemetryConstants.EXTRA_SEQ, -1);
 
         final String profileName = intent.getStringExtra(TelemetryConstants.EXTRA_PROFILE_NAME);
         final String profilePath = intent.getStringExtra(TelemetryConstants.EXTRA_PROFILE_PATH);
 
-        uploadCorePing(docId, seq, profileName, profilePath);
+        uploadCorePing(docId, seq, profileName, profilePath, defaultSearchEngine);
     }
 
     /**
      * Determines if the telemetry upload feature is enabled via the application configuration. Prefer to use
      * {@link #isUploadEnabledByProfileConfig(Context, GeckoProfile)} if the profile is available as it takes into
      * account more information.
      *
      * Note that this method logs debug statements when upload is disabled.
@@ -160,17 +162,17 @@ public class TelemetryUploadService exte
             return false;
         }
 
         return true;
     }
 
     @WorkerThread
     private void uploadCorePing(@NonNull final String docId, final int seq, @NonNull final String profileName,
-                @NonNull final String profilePath) {
+                @NonNull final String profilePath, @Nullable final String defaultSearchEngine) {
         final GeckoProfile profile = GeckoProfile.get(this, profileName, profilePath);
         final long profileCreationDate = getProfileCreationDate(profile);
         final String clientId;
         try {
             clientId = profile.getClientId();
         } catch (final IOException e) {
             Log.w(LOGTAG, "Unable to get client ID to generate core ping: returning.", e);
             return;
@@ -178,17 +180,17 @@ public class TelemetryUploadService exte
 
         // Each profile can have different telemetry data so we intentionally grab the shared prefs for the profile.
         final SharedPreferences sharedPrefs = GeckoSharedPrefs.forProfileName(this, profileName);
         // TODO (bug 1241685): Sync this preference with the gecko preference.
         final String serverURLSchemeHostPort =
                 sharedPrefs.getString(TelemetryConstants.PREF_SERVER_URL, TelemetryConstants.DEFAULT_SERVER_URL);
 
         final TelemetryPing corePing = TelemetryPingGenerator.createCorePing(this, docId, clientId,
-                serverURLSchemeHostPort, seq, profileCreationDate);
+                serverURLSchemeHostPort, seq, profileCreationDate, defaultSearchEngine);
         final CorePingResultDelegate resultDelegate = new CorePingResultDelegate();
         uploadPing(corePing, resultDelegate);
     }
 
     private void uploadPing(final TelemetryPing ping, final ResultDelegate delegate) {
         final BaseResource resource;
         try {
             resource = new BaseResource(ping.getURL());