For #6558 - added web extension for extracting document urls

app/src/main/assets/extensions/ads/ads.js

@@ -0,0 +1,17 @@
+function collect_urls(urls) {
+    let anchors = document.getElementsByTagName("a");
+    for (let anchor of anchors) {
+          if (!anchor.href) {
+            continue;
+          }
+          urls.push(anchor.href);
+    }
+}
+let urls = [];
+collect_urls(urls)
+
+let message = {
+    'url': document.location.href,
+    'urls': urls
+}
+browser.runtime.sendNativeMessage("MozacBrowserAds", message);

app/src/main/assets/extensions/ads/manifest.json

@@ -0,0 +1,24 @@
+{
+  "manifest_version": 2,
+  "name": "Mozilla Android Components - Ads",
+  "version": "1.0",
+  "content_scripts": [
+    {
+      "matches": ["https://*/*"],
+      "include_globs": [
+        "https://www.google.*/search*",
+        "https://www.baidu.com/s*",
+        "https://www.baidu.com/baidu*",
+        "https://*search.yahoo.com/search*",
+        "https://www.bing.com/search*",
+        "https://duckduckgo.com/*"
+      ],
+      "js": ["ads.js"],
+      "run_at": "document_end"
+    }
+  ],
+  "permissions": [
+    "geckoViewAddons",
+    "nativeMessaging"
+  ]
+}