Issue 3443 - Use process script instead of a frame script in Element Hiding Helper

lib/main.js

Index: lib/main.js
===================================================================
--- a/lib/main.js
+++ b/lib/main.js
@@ -42,22 +42,22 @@ request.addEventListener("load", functio
   let styleService = Cc["@mozilla.org/content/style-sheet-service;1"].getService(Ci.nsIStyleSheetService);
   let styleURI = Services.io.newURI("data:text/css," + encodeURIComponent(data), null, null);
   styleService.loadAndRegisterSheet(styleURI, Ci.nsIStyleSheetService.USER_SHEET);
   onShutdown.add(() => styleService.unregisterSheet(styleURI, Ci.nsIStyleSheetService.USER_SHEET));
 }, false);
 request.send(null);
 
 // Load our developer tools actor
-let frameScript = "chrome://elemhidehelper/content/frameScript.js?" + elementMarkerClass;
-let messageManager = Cc["@mozilla.org/globalmessagemanager;1"]
-  .getService(Ci.nsIFrameScriptLoader);
-messageManager.loadFrameScript(frameScript, true);
+let processScript = "chrome://elemhidehelper/content/processScript.js?" + elementMarkerClass;
+let messageManager = Cc["@mozilla.org/parentprocessmessagemanager;1"]
+                       .getService(Ci.nsIProcessScriptLoader);
+messageManager.loadProcessScript(processScript, true);
 onShutdown.add(() => {
-  messageManager.removeDelayedFrameScript(frameScript);
+  messageManager.removeDelayedProcessScript(processScript);
   messageManager.QueryInterface(Ci.nsIMessageBroadcaster).broadcastAsyncMessage("ElemHideHelper:Shutdown");
 });
 
 // Load overlay asynchonously and start attaching to windows once done
 request = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"].createInstance(Ci.nsIJSXMLHttpRequest);
 request.open("GET", "chrome://elemhidehelper/content/overlay.xul");
 request.channel.owner = Cc["@mozilla.org/systemprincipal;1"].getService(Ci.nsIPrincipal);
 request.addEventListener("load", function(event)