Added download feature for Unix, Linux, and MacOS systems using native messaging.

src/scripts/background.js

@@ -16,4 +16,11 @@ const handleUpdated = (tabId, changeInfo, tabInfo) => {
     }
 }
 
+const notify = (data) => {
+    let port = browser.runtime.connectNative("web_video_dl");
+    console.log("Downloding: " + data.url);
+    port.postMessage(data.url);
+}
+
+browser.runtime.onMessage.addListener(notify);
 browser.tabs.onUpdated.addListener(handleUpdated);