Issue 6036 - Use correct resolution for devtools pane icon

devtools.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present 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 17 matching lines @@
     {
       type: "prefs.get",
       key: "show_devtools_panel"
     },
     enabled =>
     {
       if (enabled)
       {
         browser.devtools.panels.create(
           "Adblock Plus",
-          "icons/detailed/abp-48.png",
+          "icons/abp-16.png",

[Wladimir Palant, 2017/11/17 12:35:41]

This API apparently accepts one icon size only, this is wrong... Either way, I
couldn't find any place where Chrome would display this icon, so I guess that
size doesn't matter there. We should use abp-32.png on Firefox however, this
will look much better on hi-DPI screens while still being ok if scaled down.

[kzar, 2017/11/17 14:22:25]

You're right, 32px doesn't look quite as good on my laptop's screen but on my
friend's retina mac screen it looks much sharper. Done.

           "devtools-panel.html",
           panel =>
           {
             panel.onShown.addListener(window =>
             {
               panelWindow = window;
             });
 
             panel.onHidden.addListener(window =>
             {
               panelWindow = null;
             });
 
             if (panel.onSearch)
             {
               panel.onSearch.addListener((eventName, queryString) =>
               {
                 if (panelWindow)
                   panelWindow.postMessage({type: eventName, queryString}, "*");
               });
             }
           }
         );
       }
     }
   );
 }