Bug 1088761 - Support reportValidity() for form controls. r=smaug

From 2c2f7223e9d88f431f3e3fee7384dffbca07d8a9 Mon Sep 17 00:00:00 2001

dom/html/HTMLFormElement.h

@@ -387,6 +387,11 @@ public:
     return CheckFormValidity(nullptr);
   }
 
+  bool ReportValidity()
+  {
+    return CheckValidFormSubmission();
+  }
+
   Element*
   IndexedGetter(uint32_t aIndex, bool &aFound);