updating notify-link-clicks-i18n to use placeholders member in messages.json files, plus getting rid of my changes that are not needed at the moment

notify-link-clicks-i18n/_locales/de/messages.json

@@ -15,7 +15,13 @@
   },
 
   "notificationContent": {
-    "message": "Du hast $1 angeklickt",
+    "message": "Du hast $URL$ angeklickt",
-    "description": "Tells the user which link they clicked: the $1 placeholder is the url."
+    "description": "Tells the user which link they clicked.",
+    "placeholders": {
+      "url" : {
+        "content" : "$1",
+        "example" : "https://developer.mozilla.org"
+      }
+    }
   }
 }

notify-link-clicks-i18n/_locales/en/messages.json

@@ -15,7 +15,13 @@
   },
 
   "notificationContent": {
-    "message": "You clicked $1.",
+    "message": "You clicked $URL$.",
-    "description": "Tells the user which link they clicked: the $1 placeholder is the url."
+    "description": "Tells the user which link they clicked.",
+    "placeholders": {
+      "url" : {
+        "content" : "$1",
+        "example" : "https://developer.mozilla.org"
+      }
+    }
   }
 }

notify-link-clicks-i18n/_locales/ja/messages.json

@@ -15,7 +15,13 @@
   },
 
   "notificationContent": {
-    "message": "$1がクリックされました。",
+    "message": "$URL$がクリックされました。",
-    "description": "リンクをクリックした時通知を表示します。:変数$1にはurlが代入されます。"
+    "description": "リンクをクリックした時通知を表示します。:変数$1にはurlが代入されます。",
+    "placeholders": {
+      "url" : {
+        "content" : "$1",
+        "example" : "https://developer.mozilla.org"
+      }
+    }
   }
 }

notify-link-clicks-i18n/_locales/nl/messages.json

@@ -15,7 +15,13 @@
   },
 
   "notificationContent": {
-    "message": "U klikte op $1",
+    "message": "U klikte op $URL$",
-    "description": "Tells the user which link they clicked: the $1 placeholder is the url."
+    "description": "Tells the user which link they clicked.",
+    "placeholders": {
+      "url" : {
+        "content" : "$1",
+        "example" : "https://developer.mozilla.org"
+      }
+    }
   }
 }

notify-link-clicks-i18n/background-script.js

@@ -9,7 +9,7 @@ function notify(message) {
   var content = chrome.i18n.getMessage("notificationContent", message.url);
   chrome.notifications.create({
     "type": "basic",
-    "iconUrl": chrome.extension.getURL("icons/__MSG_@@ui_locale__/link-48-__MSG_@@ui_locale__.png"),
+    "iconUrl": chrome.extension.getURL("icons/link-48.png"),
     "title": title,
     "message": content
   });