Bug 1345474 - Check incognito access for webRequest api r=kmag

Depends on D4112

Differential Revision: https://phabricator.services.mozilla.com/D5571

toolkit/components/extensions/webrequest/ChannelWrapper.cpp

@@ -522,6 +522,14 @@ bool ChannelWrapper::Matches(
   }
 
   if (aExtension) {
+    // Verify extension access to private requests
+    if (!aExtension->PrivateBrowsingAllowed()) {
+      nsCOMPtr<nsILoadInfo> loadInfo = GetLoadInfo();
+      if (loadInfo && loadInfo->GetOriginAttributes().mPrivateBrowsingId > 0) {
+        return false;
+      }
+    }
+
     bool isProxy =
         aOptions.mIsProxy && aExtension->HasPermission(nsGkAtoms::proxy);
     // Proxies are allowed access to all urls, including restricted urls.