Issue 1593 - Extend workaround for Chrome bug breaking Flash videos to Chrome >=38

chrome/ext/background.js

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2014 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 301 matching lines @@
         var frameId;
         if (requestType == "sub_frame")
           frameId = details.parentFrameId;
         else
           frameId = details.frameId;
 
         frame = frames[frameId] || frames[Object.keys(frames)[0]];
 
         if (frame)
         {
-          // Chrome 38 and 39 mistakenly reports requests of type 'object'
-          // (e.g. requests initiated by Flash) with the type 'other'.
+          // Since Chrome 38 requests of type 'object' (e.g. requests
+          // initiated by Flash) are mistakenly reported with the type 'other'.
           // https://code.google.com/p/chromium/issues/detail?id=410382
-          if (requestType == "other" && / Chrome\/3[8-9]\b/.test(navigator.userAgent))
+          if (requestType == "other" && parseInt(navigator.userAgent.match(/\bChrome\/(\d+)/)[1], 10) >= 38)

[Wladimir Palant, 2014/11/25 16:45:51]

This will error out if navigator.userAgent.match() returns null (shouldn't
happen too often but is possible).

Given that we are in the background page here, why not do
|Services.vc.compare(require("info").applicationVersion, "38.0") >= 0|?

[Sebastian Noack, 2014/11/25 17:04:04]

Well, in that case parseInt() will return NaN, and |NaN >= 38| returns false.
Therefore this code really is the same as:

  var match = navigator.userAgent.match(/\bChrome\/(\d+)/)[1], 10);
  if (match && parseInt(match[0], 10) >= 38)
Because we are in the abstraction layer. That's one reason why I would like to
convert ext into CommonJS modules bundled with our other code, that we can
easier reuse those functions.

             requestType = "object";
 
           if (!ext.webRequest.onBeforeRequest._dispatch(details.url, requestType, new Page({id: details.tabId}), frame))
             return {cancel: true};
         }
       }
 
       if (isMainFrame || details.type == "sub_frame")
         frames[details.frameId] = {url: details.url, parent: frame};
     }
@@ skipping 70 matching lines @@
             callback(new Page(tab));
         }
         else
         {
           ext.pages.open(optionsUrl, callback);
         }
       });
     });
   };
 })();