Bug 1465457 - Add support for chrome reftests r=dbaron

Differential Revision: https://phabricator.services.mozilla.com/D20585

--HG--
extra : moz-landing-system : lando

layout/tools/reftest/manifest.jsm

@@ -644,7 +644,6 @@ function CreateUrls(test) {
                     .getService(Ci.nsIScriptSecurityManager);
 
     let manifestURL = g.ioService.newURI(test.manifest);
-    let principal = secMan.createCodebasePrincipal(manifestURL, {});
 
     let testbase = manifestURL;
     if (test.runHttp)
@@ -656,6 +655,9 @@ function CreateUrls(test) {
             return file;
 
         var testURI = g.ioService.newURI(file, null, testbase);
+        let isChrome = testURI.scheme == "chrome";
+        let principal = isChrome ? secMan.getSystemPrincipal() :
+                                   secMan.createCodebasePrincipal(manifestURL, {});
         secMan.checkLoadURIWithPrincipal(principal, testURI,
                                          Ci.nsIScriptSecurityManager.DISALLOW_SCRIPT);
         return testURI;

layout/tools/reftest/reftest-content.js

@@ -20,6 +20,9 @@ Cu.import("resource://gre/modules/Timer.jsm");
 Cu.import("resource://reftest/AsyncSpellCheckTestHelper.jsm");
 Cu.import("resource://gre/modules/Services.jsm");
 
+// This will load chrome Custom Elements inside chrome documents:
+ChromeUtils.import("resource://gre/modules/CustomElementsListener.jsm", null);
+
 var gBrowserIsRemote;
 var gIsWebRenderEnabled;
 var gHaveCanvasSnapshot = false;

layout/tools/reftest/reftest/__init__.py

@@ -121,7 +121,7 @@ class ReftestManifest(object):
                     break
 
             for f in tests:
-                # We can't package about: or data: URIs.
+                # We can't package about:, data:, or chrome: URIs.
                 # Discarding data isn't correct for a parser. But retaining
                 # all data isn't currently a requirement.
                 if RE_PROTOCOL.match(f):