separating background apis to their own classes

src/background/runtime.background.ts

@@ -0,0 +1,26 @@
+import MainBackground from './main.background';
+
+export default class RuntimeBackground {
+    private runtime: any;
+
+    constructor(private main: MainBackground) {
+        this.runtime = chrome.runtime;
+    }
+
+    async init() {
+        if (!this.runtime || this.runtime.onInstalled) {
+            return;
+        }
+
+        this.runtime.onInstalled.addListener((details: any) => {
+            (window as any).ga('send', {
+                hitType: 'event',
+                eventAction: 'onInstalled ' + details.reason,
+            });
+
+            if (details.reason === 'install') {
+                chrome.tabs.create({ url: 'https://bitwarden.com/browser-start/' });
+            }
+        });
+    }
+}