Issue 5130 - Changes listener to register <all_urls> and filter non ws http requests

ext/background.js

Index: ext/background.js
===================================================================
--- a/ext/background.js
+++ b/ext/background.js
@@ -558,16 +558,26 @@
           }
         }
       });
     });
   });
 
   chrome.webRequest.onBeforeRequest.addListener(details =>
   {
+    // Filter out requests from non web protocols. Ideally, we'd explicitly
+    // specify the protocols we are interested in (i.e. http://, https://,
+    // ws:// and wss://) with the url patterns, given below, when adding this
+    // listener. But unfortunately, Chrome <=57 doesn't support the WebSocket
+    // protocol and is causing an error if it is given.
+    let url = new URL(details.url);

[Sebastian Noack, 2017/04/20 19:59:48]

Perhaps move this after the check below, so that we can skip parsing the URL for
top-level documents which we ignore anyway.

[Jon Sonesen, 2017/04/20 20:04:48]

Done.

+    if (url.protocol != "http:" && url.protocol != "https:" &&
+        url.protocol != "ws:" && url.protocol != "wss:")
+      return;
+
     // The high-level code isn't interested in requests that aren't
     // related to a tab or requests loading a top-level document,
     // those should never be blocked.
     if (details.tabId == -1 || details.type == "main_frame")
       return;
 
     // We are looking for the frame that contains the element which
     // has triggered this request. For most requests (e.g. images) we
@@ -579,26 +589,26 @@
       frameId = details.parentFrameId;
       type = "SUBDOCUMENT";
     }
 
     let frame = ext.getFrame(details.tabId, frameId);
     if (frame)
     {
       let results = ext.webRequest.onBeforeRequest._dispatch(
-        new URL(details.url),
+        url,

[Sebastian Noack, 2017/04/20 19:59:48]

Nit: Wrapping after each argument, while most arguments are not longer than a
few characters anymore, seems unnecessary now:

  let results = ext.webRequest.onBeforeRequest._dispatch(
    url, type.toUpperCase(), new Page({id: details.tabId}), frame
  );

[Jon Sonesen, 2017/04/20 20:04:48]

Done.

         type.toUpperCase(),
         new Page({id: details.tabId}),
         frame
       );
 
       if (results.indexOf(false) != -1)
         return {cancel: true};
     }
-  }, {urls: ["https://*/*", "http://*/*", "ws://*/*", "wss://*/*"]}, ["blocking"]);
+  }, {urls: ["<all_urls>"]}, ["blocking"]);
 
 
   /* Message passing */
 
   chrome.runtime.onMessage.addListener((message, rawSender, sendResponse) =>
   {
     let sender = {};