Bug 808608 - Remove Xray shadowing protection infrastructure. r=mrbkap

This is now unused.

js/xpconnect/wrappers/WrapperFactory.h

@@ -18,13 +18,7 @@ class WrapperFactory {
     enum { WAIVE_XRAY_WRAPPER_FLAG = js::Wrapper::LAST_USED_FLAG << 1,
            IS_XRAY_WRAPPER_FLAG    = WAIVE_XRAY_WRAPPER_FLAG << 1,
            SCRIPT_ACCESS_ONLY_FLAG = IS_XRAY_WRAPPER_FLAG << 1,
-           SOW_FLAG                = SCRIPT_ACCESS_ONLY_FLAG << 1,
-
-           // Prevent scripts from shadowing native properties.
-           // NB: Applies only to Xray wrappers.
-           // NB: This will prevent scriptable helpers from defining special
-           //     handlers for properties defined in IDL. Use with caution.
-           SHADOWING_FORBIDDEN     = SOW_FLAG << 1 };
+           SOW_FLAG                = SCRIPT_ACCESS_ONLY_FLAG << 1 };
 
     // Return true if any of any of the nested wrappers have the flag set.
     static bool HasWrapperFlag(JSObject *wrapper, unsigned flag) {
@@ -41,10 +35,6 @@ class WrapperFactory {
         return HasWrapperFlag(wrapper, WAIVE_XRAY_WRAPPER_FLAG);
     }
 
-    static bool IsShadowingForbidden(JSObject *wrapper) {
-        return HasWrapperFlag(wrapper, SHADOWING_FORBIDDEN);
-    }
-
     static JSObject *GetXrayWaiver(JSObject *obj);
     static JSObject *CreateXrayWaiver(JSContext *cx, JSObject *obj);
     static JSObject *WaiveXray(JSContext *cx, JSObject *obj);

js/xpconnect/wrappers/XrayWrapper.cpp

@@ -1461,19 +1461,6 @@ bool
 XrayWrapper<Base, Traits>::defineProperty(JSContext *cx, JSObject *wrapper, jsid id,
                                           js::PropertyDescriptor *desc)
 {
-    // If shadowing is forbidden, see if the id corresponds to an underlying
-    // native property.
-    if (WrapperFactory::IsShadowingForbidden(wrapper)) {
-        JSObject *holder = Traits::singleton.ensureHolder(cx, wrapper);
-        js::PropertyDescriptor nativeProp;
-        if (!Traits::resolveNativeProperty(cx, wrapper, holder, id, false, &nativeProp))
-            return false;
-        if (nativeProp.obj) {
-            JS_ReportError(cx, "Permission denied to shadow native property");
-            return false;
-        }
-    }
-
     // Redirect access straight to the wrapper if we should be transparent.
     if (XrayUtils::IsTransparent(cx, wrapper)) {
         JSObject *obj = Traits::getTargetObject(wrapper);