Chrome Extension to replace the standard CKEditor configuration with one of my control in the Salesforce success forums

background.js

chrome.webRequest.onBeforeRequest.addListener(
    function(details) {
         //return {redirectUrl: 'https://developer.salesforce.com/forums/ckeditor/ckeditor-5.x/rel/sfdc-config.js'};
		 return {redirectUrl: 'https://na5.salesforce.com/resource/1447106281000/DFB__sfdcConfig'};
    },
    {
        urls: [
            "https://developer.salesforce.com/forums/ckeditor/ckeditor-4.x/rel/sfdc-config.js",
            "https://developer.salesforce.com/forums/ckeditor/ckeditor-4.x/rel/sfdc-config.js?t=4.4.6.4"
        ],
        types: ["script", "main_frame", "sub_frame", "stylesheet", "image", "object", "xmlhttprequest", "other"] 
    },
    ["blocking"]
);

config.js

// Chrome Extension Version
alert('injected');
CKEDITOR.editorConfig = function(a) {
    a.toolbarCanCollapse = true;
    a.resize_enabled = true;
    a.enterMode = CKEDITOR.ENTER_BR;
    a.shiftEnterMode = CKEDITOR.ENTER_P;
    a.forcePasteAsPlainText = true;
    a.forceSimpleAmpersand = true;
    a.pasteFromWordRemoveFontStyles = true;
    a.pasteFromWordRemoveStyles = true;
    a.imageUploadAllowedExtensions = ".(jpg|gif|jpeg|png|bmp|jfif|jpe|pjpeg)$";
    a.imageUploadDeniedExtensions = "";
    var b = [];
    b.push("div{*}(*); span{*}(*); p{*}(*); br{*}(*); hr{*}(*);");
    b.push("h1{*}(*); h2{*}(*); h3{*}(*); h4{*}(*); h5{*}(*); h6{*}(*);");
    b.push("a[*]{*}(*);");
    b.push("img[!src,alt,width,height,border]{*}(*);");
    b.push("font[face,size,color];");
    b.push("strike; s; b; em; strong; i; big; small; sub; sup; blockquote; ins; kbd; pre{*}(*); tt;");
    b.push("abbr; acronym; address; bdo; caption; cite; code; col; colgroup;");
    b.push("dd; del; dfn; dl; dt; q; samp; var;");
    b.push("table{*}(*)[align,border,cellpadding,cellspacing,summary];");
    b.push("caption{*}(*); tbody{*}(*); thead{*}(*); tfoot{*}(*);");
    b.push("th{*}(*)[scope,colspan,rowspan,align,valign]; tr{*}(*)[align,valign]; td{*}(*)[scope,colspan,rowspan,align,valign];");
    a.extraAllowedContent = b.join(" ");
    a.coreStyles_strike = {
        element: "strike"
    };
    a.coreStyles_bold = {
        element: "b"
    };
    a.coreStyles_italic = {
        element: "i"
    };
    //a.removePlugins = "elementspath,maximize,resize,image,liststyle,tabletools,contextmenu";
	a.removePlugins = "elementspath,maximize,resize,image,liststyle,tabletools,contextmenu,scayt,menubutton"; 
	a.disableNativeSpellChecker = false;
    a.extraPlugins = "sfdcImage,sfdcMediaEmbed,sfdcSmartLink,sfdcCodeBlock,sfdcTable,sfdcVfAjax4J";
    //a.removeDialogTabs = "link:advanced;table:advanced;tableProperties:advanced";
    a.toolbar_SalesforceBasic = [
        ["Undo", "Redo"],
        ["Bold", "Italic", "Underline", "Strike"],
        ["-", "Link", "sfdcImage"],
        ["-",
            "JustifyLeft", "JustifyCenter", "JustifyRight"
        ],
        ["-", "BulletedList", "NumberedList"],
        ["Indent", "Outdent"]
    ];
    a.toolbar_SalesforceLight = [
        ["Bold", "Italic"],
        ["Link"],
        ["JustifyLeft", "JustifyCenter", "JustifyRight"],
        ["BulletedList"],
        ["FontSize"]
    ];
    a.toolbar_EmailMultiFormat = [
        ["SfdcSwitchToText"],
        ["RemoveFormat", "TextColor", "BGColor"],
        ["Bold", "Italic", "Underline", "Strike"],
        ["sfdcImage"],
        ["Link", "Unlink", "Anchor"],
        ["JustifyLeft", "JustifyCenter", "JustifyRight"],
        ["BulletedList", "NumberedList", "Indent", "Outdent"],
        ["Font", "FontSize", "Format"]
    ];
    a.toolbar_Email = [
        ["RemoveFormat", "TextColor", "BGColor"],
        ["Bold", "Italic", "Underline", "Strike"],
        ["sfdcImage"],
        ["Link", "Unlink", "Anchor"],
        ["JustifyLeft", "JustifyCenter", "JustifyRight"],
        ["BulletedList", "NumberedList", "Indent", "Outdent"],
        ["Font", "FontSize", "Format"]
    ];
    a.toolbar_Knowledge = [
        ["Source"],
        ["Undo", "Redo"], "Bold Italic Underline Strike - RemoveFormat".split(" "), ["Table", "sfdcCodeBlock"],
        ["sfdcSmartLink", "Link", "Unlink", "Anchor"],
        ["sfdcImage"],
        ["JustifyLeft", "JustifyCenter",
            "JustifyRight"
        ],
        ["BulletedList", "NumberedList", "Indent", "Outdent"],
        ["Format", "Font", "FontSize", "TextColor", "BGColor"]
    ];
    a.toolbar_KnowledgeWithIframes = [
        ["Source"],
        ["Undo", "Redo"], "Bold Italic Underline Strike - RemoveFormat".split(" "), ["Table", "sfdcCodeBlock"],
        ["sfdcSmartLink", "Link", "Unlink", "Anchor"],
        ["sfdcImage", "sfdcMediaEmbed"],
        ["JustifyLeft", "JustifyCenter", "JustifyRight"],
        ["BulletedList", "NumberedList", "Indent", "Outdent"],
        ["Format", "Font", "FontSize", "TextColor", "BGColor"]
    ];
    a.toolbar_Visualforce = [
        ["Undo", "Redo"],
        ["Bold", "Italic", "Underline", "Strike"],
        ["Link", "sfdcImage"],
        ["JustifyLeft", "JustifyCenter", "JustifyRight"],
        ["BulletedList", "NumberedList", "Indent", "Outdent"]
    ];
    a.toolbar_HomePageComponent = [
        ["Undo", "Redo"],
        ["Bold", "Italic", "Underline", "Strike"],
        ["Table"],
        ["Link", "sfdcImage"],
        ["JustifyLeft", "JustifyCenter", "JustifyRight"],
        ["BulletedList", "NumberedList", "Indent", "Outdent"],
        ["Font", "FontSize", "TextColor", "BGColor"]
    ];
    a.toolbar_ServiceCommunity = [
		["Source", "RemoveFormat"],
        ["Undo", "Redo"],
        ["Bold", "Italic", "Underline", "Strike"],
        ["Link", "sfdcImage", "sfdcCodeBlock"],
        ["JustifyLeft", "JustifyCenter", "JustifyRight"],
        ["BulletedList", "NumberedList", "Indent", "Outdent"]
    ];
    a.plugins = "about,a11yhelp,basicstyles,bidi,blockquote,clipboard,colorbutton,colordialog,contextmenu,dialogadvtab,div,elementspath,enterkey,entities,filebrowser,find,flash,floatingspace,font,format,forms,horizontalrule,htmlwriter,image,iframe,indentlist,indentblock,justify,language,link,list,liststyle,magicline,maximize,newpage,pagebreak,pastefromword,pastetext,preview,print,removeformat,resize,save,selectall,showblocks,showborders,smiley,sourcearea,specialchar,stylescombo,tab,table,tabletools,templates,toolbar,undo,wysiwygarea"
};

manifest.json

{
  "name": "Salesforce Forum Spellchecker",
  "description": "Replace CKEditor config.js to enable spell checking",
  "version": "1.0",
  "manifest_version": 1,
  "background": {"scripts":["background.js"]},
  "permissions": [
    "webRequest",
    "https://developer.salesforce.com/*",
    "webRequestBlocking"
  ]
}