Issue 5028 - Use browser namespace

ext/content.js

 "use strict";
 
 // Firefox 55 erroneously sends messages from the content script to the
 // devtools panel:
 // https://bugzilla.mozilla.org/show_bug.cgi?id=1383310
 // As a workaround, listen for messages only if this isn't the devtools panel.
-// Note that Firefox processes API access lazily, so chrome.devtools will always
-// exist but will have undefined as its value on other pages.
-if (!chrome.devtools)
+// Note that Firefox processes API access lazily, so browser.devtools will
+// always exist but will have undefined as its value on other pages.
+if (!browser.devtools)
 {
   // Listen for messages from the background page.
-  chrome.runtime.onMessage.addListener((message, sender, sendResponse) =>
+  browser.runtime.onMessage.addListener((message, sender, sendResponse) =>
   {
     return ext.onMessage._dispatch(message, {}, sendResponse).includes(true);
   });
 }
 
 (function()
 {
   let port = null;
 
   ext.onExtensionUnloaded = {
     addListener(listener)
     {
       if (!port)
-        port = chrome.runtime.connect();
+        port = browser.runtime.connect();
 
       // When the extension is reloaded, disabled or uninstalled the
       // background page dies and automatically disconnects all ports
       port.onDisconnect.addListener(listener);
     },
     removeListener(listener)
     {
       if (port)
       {
         port.onDisconnect.removeListener(listener);
 
         if (!port.onDisconnect.hasListeners())
         {
           port.disconnect();
           port = null;
         }
       }
     }
   };
 }());