Bug 22457: Allow resources loaded by view-source://

Instead of whitelisting single resources for view-source requests that
might allow platform detection we allow all of those that are needed by
requests with a view-source origin. This should be safe now that
https://bugzilla.mozilla.org/show_bug.cgi?id=1172165 landed.

src/components/content-policy.js

@@ -83,8 +83,12 @@ ContentPolicy.prototype = {
       return Ci.nsIContentPolicy.ACCEPT;
     }
 
-    // Accept if no origin URI or if origin scheme is chrome/resource/about.
-    if (!aRequestOrigin || aRequestOrigin.schemeIs('resource') || aRequestOrigin.schemeIs('chrome') || aRequestOrigin.schemeIs('about'))
+    // Accept if no origin URI or if origin scheme is
+    // chrome/resource/about/view-source.
+    if (!aRequestOrigin || aRequestOrigin.schemeIs('resource') ||
+                           aRequestOrigin.schemeIs('chrome') ||
+                           aRequestOrigin.schemeIs('about') ||
+                           aRequestOrigin.schemeIs('view-source'))
       return Ci.nsIContentPolicy.ACCEPT;
 
     // Accept if resource directly loaded into a tab.