Bug 810520. Correctly handle static methods and attributes in the NativeProperties structs that Xrays use. r=peterv

Note that at this point we actaully do Xrays for all of our various
property types, except in worker code.  The real substantive change
here is the change to what usedForXrays returns.  The rest is minor
cleanup.

dom/bindings/Codegen.py

@@ -1027,11 +1027,8 @@ class PropertyDefiner:
                 return "s" + self.name
         return "nullptr"
     def usedForXrays(self):
-        # We only need Xrays for methods, attributes and constants, but in
-        # workers there are no Xrays.
-        return (self.name is "Methods" or self.name is "Attributes" or
-                self.name is "UnforgeableAttributes" or
-                self.name is "Constants") and not self.descriptor.workers
+        # No Xrays in workers.
+        return not self.descriptor.workers
 
     def __str__(self):
         # We only need to generate id arrays for things that will end
@@ -1364,14 +1361,11 @@ class CGNativeProperties(CGList):
             for array in properties.arrayNames():
                 propertyArray = getattr(properties, array)
                 if check(propertyArray):
-                    if descriptor.workers:
-                        props = "%(name)s, nullptr, %(name)s_specs"
+                    if propertyArray.usedForXrays():
+                        ids = "%(name)s_ids"
                     else:
-                        if propertyArray.usedForXrays():
-                            ids = "%(name)s_ids"
-                        else:
-                            ids = "nullptr"
-                        props = "%(name)s, " + ids + ", %(name)s_specs"
+                        ids = "nullptr"
+                    props = "%(name)s, " + ids + ", %(name)s_specs"
                     props = (props %
                              { 'name': propertyArray.variableName(chrome) })
                 else:
@@ -1380,10 +1374,15 @@ class CGNativeProperties(CGList):
             return CGWrapper(CGIndenter(CGList(nativeProps, ",\n")),
                              pre="static const NativeProperties %s = {\n" % name,
                              post="\n};")
-        
-        regular = generateNativeProperties("sNativeProperties", False)
-        chrome = generateNativeProperties("sChromeOnlyNativeProperties", True)
-        CGList.__init__(self, [regular, chrome], "\n\n")
+
+        nativeProperties = []
+        if properties.hasNonChromeOnly():
+            nativeProperties.append(
+                generateNativeProperties("sNativeProperties", False))
+        if properties.hasChromeOnly():
+            nativeProperties.append(
+                generateNativeProperties("sChromeOnlyNativeProperties", True))
+        CGList.__init__(self, nativeProperties, "\n\n")
 
     def declare(self):
         return ""

dom/tests/mochitest/chrome/test_sandbox_bindings.xul

@@ -181,6 +181,16 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=741267
         ok(false, "NodeList.prototype manipulation via an Xray shouldn't throw" + e);
       }
 
+      try {
+        var url = Components.utils.evalInSandbox("URL", sandbox);
+        for (var i in url) {
+          url[i];
+        }
+        ok(true, "We didn't crash!");
+      } catch (e) {
+        ok(false, "URL interface object manipulation via an Xray shouldn't throw" + e);
+      }
+
       SimpleTest.finish();
     }