Issue 4866 - Add the child-src CSP directive back again for now

lib/csp.js

Index: lib/csp.js
diff --git a/lib/csp.js b/lib/csp.js
index b1241a1873626aa212f6223969e574f2c4807c8b..fcbd40ef67b888e2ccf1d305fc7229c56227a585 100644
--- a/lib/csp.js
+++ b/lib/csp.js
@@ -34,13 +34,17 @@ chrome.webRequest.onHeadersReceived.addListener(details =>
       // since the Chrome extension API does not allow us to intercept them.
       // https://bugs.chromium.org/p/chromium/issues/detail?id=129353
       //
-      // We also need the frame-src and object-src restrictions since CSPs are
+      // We also need the child-src and object-src restrictions since CSPs are
       // not inherited from the parent for documents with data: and blob: URLs.
       // https://bugs.chromium.org/p/chromium/issues/detail?id=513860
       //
+      // We must use the deprecated child-src directive instead of the
+      // combination of frame-src and worker-src directives since worker-src
+      // is not yet supported (as of Chrome 56.)
+      //
       // "http:" also includes "https:" implictly.
       // https://www.chromestatus.com/feature/6653486812889088
-      value: "connect-src http:; frame-src http:; object-src http:"
+      value: "connect-src http:; child-src http:; object-src http:"

[Wladimir Palant, 2017/03/01 13:17:58]

1.12.4 was using both frame-src and child-src. For the sake of not introducing
regressions shortly before a release, I suggest that you add child-src in
addition to frame-src instead of replacing it.

[kzar, 2017/03/01 14:41:18]

Done.

     });
     return {responseHeaders: details.responseHeaders};
   }