Bug 874787. Add support for legacycaller on proxy bindings. r=efaust,peterv

dom/bindings/Codegen.py

@@ -270,16 +270,18 @@ class CGDOMProxyJSClass(CGThing):
     def declare(self):
         return ""
     def define(self):
+        callHook = LEGACYCALLER_HOOK_NAME if self.descriptor.operations["LegacyCaller"] else 'nullptr'
         return """
 static const DOMJSClass Class = {
   PROXY_CLASS_DEF("%s",
                   0, /* extra slots */
                   JSCLASS_IS_DOMJSCLASS,
-                  nullptr, /* call */
+                  %s, /* call */
                   nullptr  /* construct */),
 %s
 };
 """ % (self.descriptor.interface.identifier.name,
+       callHook,
        CGIndenter(CGGeneric(DOMClass(self.descriptor))).define())
 
 def PrototypeIDAndDepth(descriptor):

dom/bindings/Configuration.py

@@ -353,10 +353,6 @@ class Descriptor(DescriptorProvider):
                     raise SyntaxError("%s supports named properties but does "
                                       "not have a named getter.\n%s" %
                                       (self.interface, self.interface.location))
-                if operations['LegacyCaller']:
-                    raise SyntaxError("%s has a legacy caller but is a proxy; "
-                                      "we don't support that yet.\n%s" %
-                                      (self.interface, self.interface.location))
                 iface = self.interface
                 while iface:
                     iface.setUserData('hasProxyDescendant', True)

dom/bindings/test/TestBindingHeader.h

@@ -967,6 +967,7 @@ public:
   uint32_t Item(uint32_t&);
   uint32_t Item(uint32_t, bool&) MOZ_DELETE;
   uint32_t Length();
+  void LegacyCall(JS::Handle<JS::Value>);
 };
 
 class TestNamedGetterInterface : public nsISupports,

dom/bindings/test/TestCodeGen.webidl

@@ -876,6 +876,7 @@ dictionary DictForConstructor {
 interface TestIndexedGetterInterface {
   getter long item(unsigned long idx);
   readonly attribute unsigned long length;
+  legacycaller void();
 };
 
 interface TestNamedGetterInterface {