Bug 897913 part 3. Enable Promise in chrome and certified apps, even when preffed off. r=bholley, pending review from baku

dom/promise/Makefile.in

@@ -13,4 +13,9 @@ LIBRARY_NAME     = dompromise_s
 LIBXUL_LIBRARY = 1
 FAIL_ON_WARNINGS := 1
 
+LOCAL_INCLUDES += \
+  -I$(topsrcdir)/dom/workers \
+  -I$(topsrcdir)/dom/base \
+  $(NULL)
+
 include $(topsrcdir)/config/rules.mk

dom/promise/Promise.cpp

@@ -11,6 +11,8 @@
 #include "PromiseCallback.h"
 #include "nsContentUtils.h"
 #include "nsPIDOMWindow.h"
+#include "WorkerPrivate.h"
+#include "nsJSPrincipals.h"
 
 namespace mozilla {
 namespace dom {
@@ -110,6 +112,26 @@ Promise::PrefEnabled()
   return Preferences::GetBool("dom.promise.enabled", false);
 }
 
+/* static */ bool
+Promise::EnabledForScope(JSContext* aCx, JSObject* /* unused */)
+{
+  // Enable if the pref is enabled or if we're chrome or if we're a
+  // certified app.
+  if (PrefEnabled()) {
+    return true;
+  }
+
+  // Note that we have no concept of a certified app in workers.
+  // XXXbz well, why not?
+  if (!NS_IsMainThread()) {
+    return workers::GetWorkerPrivateFromContext(aCx)->IsChromeWorker();
+  }
+
+  nsIPrincipal* prin = nsContentUtils::GetSubjectPrincipal();
+  return nsContentUtils::IsSystemPrincipal(prin) ||
+    prin->GetAppStatus() == nsIPrincipal::APP_STATUS_CERTIFIED;
+}
+
 static void
 EnterCompartment(Maybe<JSAutoCompartment>& aAc, JSContext* aCx,
                  const Optional<JS::Handle<JS::Value> >& aValue)
@@ -125,8 +147,6 @@ EnterCompartment(Maybe<JSAutoCompartment>& aAc, JSContext* aCx,
 Promise::Constructor(const GlobalObject& aGlobal, JSContext* aCx,
                      PromiseInit& aInit, ErrorResult& aRv)
 {
-  MOZ_ASSERT(PrefEnabled());
-
   nsCOMPtr<nsPIDOMWindow> window = do_QueryInterface(aGlobal.Get());
   if (!window) {
     aRv.Throw(NS_ERROR_UNEXPECTED);
@@ -155,8 +175,6 @@ Promise::Constructor(const GlobalObject& aGlobal, JSContext* aCx,
 Promise::Resolve(const GlobalObject& aGlobal, JSContext* aCx,
                  JS::Handle<JS::Value> aValue, ErrorResult& aRv)
 {
-  MOZ_ASSERT(PrefEnabled());
-
   nsCOMPtr<nsPIDOMWindow> window = do_QueryInterface(aGlobal.Get());
   if (!window) {
     aRv.Throw(NS_ERROR_UNEXPECTED);
@@ -174,8 +192,6 @@ Promise::Resolve(const GlobalObject& aGlobal, JSContext* aCx,
 Promise::Reject(const GlobalObject& aGlobal, JSContext* aCx,
                 JS::Handle<JS::Value> aValue, ErrorResult& aRv)
 {
-  MOZ_ASSERT(PrefEnabled());
-
   nsCOMPtr<nsPIDOMWindow> window = do_QueryInterface(aGlobal.Get());
   if (!window) {
     aRv.Throw(NS_ERROR_UNEXPECTED);

dom/promise/Promise.h

@@ -41,6 +41,7 @@ public:
   ~Promise();
 
   static bool PrefEnabled();
+  static bool EnabledForScope(JSContext* aCx, JSObject* /* unused */);
 
   // WebIDL
 

dom/webidl/Promise.webidl

@@ -7,6 +7,7 @@
  * http://dom.spec.whatwg.org/#promises
  */
 
+[Func="mozilla::dom::Promise::EnabledForScope"]
 interface PromiseResolver {
   // TODO bug 875289 - void fulfill(optional any value);
   void resolve(optional any value);
@@ -16,12 +17,18 @@ interface PromiseResolver {
 callback PromiseInit = void (PromiseResolver resolver);
 callback AnyCallback = any (optional any value);
 
-[PrefControlled, Constructor(PromiseInit init)]
+[Func="mozilla::dom::Promise::EnabledForScope", Constructor(PromiseInit init)]
 interface Promise {
   // TODO bug 875289 - static Promise fulfill(any value);
-  [Creator, Throws]
+
+  // Disable the static methods when the interface object is supposed to be
+  // disabled, just in case some code decides to walk over to .constructor from
+  // the proto of a promise object or someone screws up and manages to create a
+  // Promise object in this scope without having resolved the interface object
+  // first.
+  [Creator, Throws, Func="mozilla::dom::Promise::EnabledForScope"]
   static Promise resolve(any value); // same as any(value)
-  [Creator, Throws]
+  [Creator, Throws, Func="mozilla::dom::Promise::EnabledForScope"]
   static Promise reject(any value);
 
   [Creator]