Issue 3452 - Bring back $ping type option (Core changes)

lib/contentPolicy.js

Index: lib/contentPolicy.js
===================================================================
--- a/lib/contentPolicy.js
+++ b/lib/contentPolicy.js
@@ -38,27 +38,27 @@ let {ElemHide} = require("elemHide");
 var Policy = exports.Policy =
 {
   /**
    * Set of explicitly supported content types
    * @type Set.<string>
    */
   contentTypes: new Set([
     "OTHER", "SCRIPT", "IMAGE", "STYLESHEET", "OBJECT", "SUBDOCUMENT", "DOCUMENT",
-    "XMLHTTPREQUEST", "OBJECT_SUBREQUEST", "FONT", "MEDIA", "ELEMHIDE", "POPUP",
-    "GENERICHIDE", "GENERICBLOCK"
+    "XMLHTTPREQUEST", "OBJECT_SUBREQUEST", "FONT", "MEDIA", "PING", "ELEMHIDE",
+    "POPUP", "GENERICHIDE", "GENERICBLOCK"
   ]),
 
   /**
    * Set of content types that aren't associated with a visual document area
    * @type Set.<string>
    */
   nonVisualTypes: new Set([
     "SCRIPT", "STYLESHEET", "XMLHTTPREQUEST", "OBJECT_SUBREQUEST", "FONT",
-    "ELEMHIDE", "POPUP", "GENERICHIDE", "GENERICBLOCK"
+    "PING", "ELEMHIDE", "POPUP", "GENERICHIDE", "GENERICBLOCK"
   ]),
 
   /**
    * Map containing all schemes that should be ignored by content policy.
    * @type Set.<string>
    */
   whitelistSchemes: new Set(),
 
@@ -120,16 +120,21 @@ var Policy = exports.Policy =
     {
       return {allow, collapse, hits};
     }
 
     // Ignore whitelisted schemes
     if (!this.isBlockableScheme(location))
       return response(true, false);
 
+    // Treat navigator.sendBeacon() the same as <a ping>, it's essentially the
+    // same concept - merely generalized.

[Sebastian Noack, 2015/12/23 13:34:45]

I'm inclined to also add a note that we cannot distinguis BEACON and PING on
Chrome anyway.

[Wladimir Palant, 2015/12/23 14:14:34]

That means fairly little for Firefox - we wouldn't dumb down our Firefox
extension because of Chrome if distinguishing the types made sense.

[Sebastian Noack, 2015/12/23 14:18:18]

Well, given that Chrome is our largest platform, I think the feasibility of
implementing a filter there, should be something we should consider, when adding
new filters.

+    if (contentType == "BEACON")
+      contentType = "PING";
+
     // Interpret unknown types as "other"
     if (!this.contentTypes.has(contentType))
       contentType = "OTHER";
 
     let wndLocation = frames[0].location;
     let docDomain = getHostname(wndLocation);
     let match = null;
     let [sitekey, sitekeyFrame] = getSitekey(frames);