Issue 4364 - Drop support for Chrome 29-40 and remove legacy code

include.preload.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 317 matching lines @@
   },
 
   disconnect: function()
   {
     document.removeEventListener("DOMContentLoaded", this.trace);
     this.observer.disconnect();
     clearTimeout(this.timeout);
   }
 };
 
-function runInDocument(fn, arg)

[kzar, 2016/08/30 13:14:09]

Since this no longer takes a document argument perhaps it should be called
runInPage again? (Or something else?)

[Sebastian Noack, 2016/09/09 14:39:50]

How about runInPageContext()? No preference though, I don't think there is a
good term for that.

[kzar, 2016/09/13 12:30:01]

Sounds good to me.

+function runInPageContext(fn, arg)
 {
   var script = document.createElement("script");
   script.type = "application/javascript";
   script.async = false;
   script.textContent = "(" + fn + ")(" + JSON.stringify(arg) + ");";
   document.documentElement.appendChild(script);
   document.documentElement.removeChild(script);
 }
 
 // Neither Chrome[1] nor Safari allow us to intercept WebSockets, and therefore
@@ skipping 14 matching lines @@
       type: "request.websocket",
       url: event.detail.url
     }, function (block)
     {
       document.dispatchEvent(
         new CustomEvent(eventName + "-" + event.detail.url, {detail: block})
       );
     });
   });
 
-  runInDocument(function(eventName)
+  runInPageContext(function(eventName)
   {
     // As far as possible we must track everything we use that could be
     // sabotaged by the website later in order to circumvent us.
     var RealWebSocket = WebSocket;
     var closeWebSocket = Function.prototype.call.bind(RealWebSocket.prototype.close);
     var addEventListener = document.addEventListener.bind(document);
     var removeEventListener = document.removeEventListener.bind(document);
     var dispatchEvent = document.dispatchEvent.bind(document);
     var CustomEvent = window.CustomEvent;
 
@@ skipping 41 matching lines @@
       CLOSED: {value: RealWebSocket.CLOSED, enumerable: true},
       prototype: {value: RealWebSocket.prototype}
     });
 
     RealWebSocket.prototype.constructor = WebSocket;
   }, eventName);
 }
 
 function ElemHide()
 {
   this.shadow = this.createShadowTree();

[kzar, 2016/08/30 13:14:09]

I don't mind too much but perhaps this.shadow should instead be a getter that
caches the result?

[Sebastian Noack, 2016/09/09 14:39:51]

Why adding more code just for the matter of using a getter? Note the comment
explaining why we have to create the shadow root no matter what.

[kzar, 2016/09/13 12:30:01]

Acknowledged.

   this.style = null;
   this.tracer = null;
 
   this.propertyFilters = new CSSPropertyFilters(
     window,
     function(callback)
     {
       ext.backgroundPage.sendMessage({
         type: "filters.get",
         what: "cssproperties"
       }, callback);
     },
     this.addSelectors.bind(this)
   );
 }
 ElemHide.prototype = {
   selectorGroupSize: 200,
 
   createShadowTree: function()
   {
-    // Use Shadow DOM if available to don't mess with web pages that rely

[kzar, 2016/08/30 13:14:09]

Nit: Should be "...if available as to not mess with..."

[Sebastian Noack, 2016/09/09 14:39:51]

Done.

-    // on the order of their own <style> tags (#309). However, creating a
-    // shadow root breaks running CSS transitions. So we have to create
+    // Use Shadow DOM if available as to not mess with with web pages that
+    // rely on the order of their own <style> tags (#309). However, creating
+    // a shadow root breaks running CSS transitions. So we have to create
     // the shadow root before transistions might start (#452).
     if (!("createShadowRoot" in document.documentElement))
       return null;
 
     // Using shadow DOM causes issues on some Google websites,
     // including Google Docs, Gmail and Blogger (#1770, #2602, #2687).
     if (/\.(?:google|blogger)\.com$/.test(document.domain))
       return null;
 
     var shadow = document.documentElement.createShadowRoot();

[kzar, 2016/08/30 13:14:09]

If we don't turn shadow into a getter perhaps we should just assign this.shadow
here instead of having the shadow variable?

[Sebastian Noack, 2016/09/09 14:39:50]

We still need to indicate whether we are using shadow DOM, in order to convert
the selectors accordingly. So while this would slightly simplify the code
injecting the stylesheet, it would require adding another property.

[kzar, 2016/09/13 12:30:01]

Acknowledged.

     shadow.appendChild(document.createElement("shadow"));
 
     // Stop the website from messing with our shadow root (#4191, #4298).
     if ("shadowRoot" in Element.prototype)
     {
-      runInDocument(function()
+      runInPageContext(function()
       {
         var ourShadowRoot = document.documentElement.shadowRoot;
         var desc = Object.getOwnPropertyDescriptor(Element.prototype, "shadowRoot");
         var shadowRoot = Function.prototype.call.bind(desc.get);
 
         Object.defineProperty(Element.prototype, "shadowRoot", {
           configurable: true, enumerable: true, get: function()
           {
             var shadow = shadowRoot(this);
             return shadow == ourShadowRoot ? null : shadow;
@@ skipping 107 matching lines @@
     checkCollapse(event.target);
   }, true);
 
   document.addEventListener("load", function(event)
   {
     var element = event.target;
     if (/^i?frame$/.test(element.localName))
       checkCollapse(element);
   }, true);
 }