--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -1493,19 +1493,16 @@ var gBrowserInit = {
         window.focus();
       } else {
         // Note: loadOneOrMoreURIs *must not* be called if window.arguments.length >= 3.
         // Such callers expect that window.arguments[0] is handled as a single URI.
         loadOneOrMoreURIs(uriToLoad, Services.scriptSecurityManager.getSystemPrincipal());
       }
     }
 
-    // Bug 778855 - Perf regression if we do this here. To be addressed in bug 779008.
-    setTimeout(function() { SafeBrowsing.init(); }, 2000);
-
     Services.obs.addObserver(gIdentityHandler, "perm-changed");
     Services.obs.addObserver(gRemoteControl, "remote-active");
     Services.obs.addObserver(gSessionHistoryObserver, "browser:purge-session-history");
     Services.obs.addObserver(gStoragePressureObserver, "QuotaManager::StoragePressure");
     Services.obs.addObserver(gXPInstallObserver, "addon-install-disabled");
     Services.obs.addObserver(gXPInstallObserver, "addon-install-started");
     Services.obs.addObserver(gXPInstallObserver, "addon-install-blocked");
     Services.obs.addObserver(gXPInstallObserver, "addon-install-origin-blocked");

--- a/browser/components/nsBrowserGlue.js
+++ b/browser/components/nsBrowserGlue.js
@@ -15,16 +15,19 @@ Cu.import("resource://gre/modules/AppCon
 
 XPCOMUtils.defineLazyServiceGetter(this, "WindowsUIUtils", "@mozilla.org/windows-ui-utils;1", "nsIWindowsUIUtils");
 XPCOMUtils.defineLazyGetter(this, "WeaveService", () =>
   Cc["@mozilla.org/weave/service;1"].getService().wrappedJSObject
 );
 XPCOMUtils.defineLazyModuleGetter(this, "ContextualIdentityService",
                                   "resource://gre/modules/ContextualIdentityService.jsm");
 
+XPCOMUtils.defineLazyModuleGetter(this, "SafeBrowsing",
+                                  "resource://gre/modules/SafeBrowsing.jsm");
+
 // lazy module getters
 
 /* global AboutHome:false, AboutNewTab:false, AddonManager:false, AppMenuNotifications:false,
           AsyncPrefs: false, AsyncShutdown:false, AutoCompletePopup:false, BookmarkHTMLUtils:false,
           BookmarkJSONUtils:false, BrowserUITelemetry:false, BrowserUsageTelemetry:false,
           ContentClick:false, ContentPrefServiceParent:false, ContentSearch:false,
           DateTimePickerHelper:false, DirectoryLinksProvider:false,
           ExtensionsUI:false, Feeds:false,
@@ -1180,16 +1183,20 @@ BrowserGlue.prototype = {
       });
     }
 
     // Let's load the contextual identities.
     Services.tm.idleDispatchToMainThread(() => {
       ContextualIdentityService.load();
     });
 
+    Services.tm.idleDispatchToMainThread(() => {
+      SafeBrowsing.init();
+    }, 5000);
+
     this._sanitizer.onStartup();
     E10SAccessibilityCheck.onWindowsRestored();
   },
 
   _createExtraDefaultProfile() {
     if (!AppConstants.MOZ_DEV_EDITION) {
       return;
     }