Issue 5316 - Adds supported filter types export value to requestBlocker

lib/requestBlocker.js

Index: lib/requestBlocker.js
===================================================================
--- a/lib/requestBlocker.js
+++ b/lib/requestBlocker.js
@@ -48,16 +48,28 @@
   // Treat navigator.sendBeacon() the same as <a ping>, it's essentially the
   // same concept - merely generalized.
   yield ["beacon", "PING"];
 
   // Treat <img srcset> and <picture> the same as other images.
   yield ["imageset", "IMAGE"];
 }());
 
+exports.filterTypes = new Set(function*()
+{
+  if (!(chrome.webRequest.ResourceType))

[Sebastian Noack, 2017/09/05 18:08:10]

Please add a comment like this:

"Microsoft Edge does not have webRequest.ResourceType. However, since
filterTypes is only used by the devtools panel which isn't supported either on
Microsoft Edge, we can just bail out here."

[Jon Sonesen, 2017/09/06 12:55:43]

Acknowledged.

+    return;
+  for (let type in chrome.webRequest.ResourceType)
+    yield resourceTypes.get(chrome.webRequest.ResourceType[type]) || "OTHER";
+  yield "WEBSOCKET";

[Sebastian Noack, 2017/09/05 18:08:11]

Please add a comment like this:

"WEBSOCKET and WEBRTC are supported through workarounds, even if the webRequest
API is lacking support to block these kind of requests."

[Jon Sonesen, 2017/09/06 12:55:43]

Acknowledged.

+  yield "WEBRTC";
+  yield "POPUP";

[Sebastian Noack, 2017/09/05 18:08:10]

Please add a comment like this:

"POPUP and ELEMHIDE filters aren't blocked on the request level but by other
means, hence they don't have a corresponding value in webRequest.ResourceType."

[Jon Sonesen, 2017/09/06 12:55:43]

Acknowledged.

+  yield "ELEMHIDE";
+}());
+
 function onBeforeRequestAsync(page, url, type, docDomain,
                               thirdParty, sitekey,
                               specificOnly, filter)
 {
   if (filter)
     FilterNotifier.emit("filter.hitCount", filter, 0, 0, page);
 
   if (devtools)