Make all attributes for SecurityPolicyViolationEventInit dict optional (#645)

The dictionary SecurityPolicyViolationEventInit is optional in the constructor of SecurityPolicyViolationEvent. This change removes the required attributes from the properties of this dictionary and adds default values to them.

Author: SaeidEid

index.bs

@@ -1599,18 +1599,18 @@ this algorithm returns normally if compilation is allowed, and throws a
     };
 
     dictionary SecurityPolicyViolationEventInit : EventInit {
-        required USVString      documentURI;
-                 USVString      referrer = "";
-                 USVString      blockedURI = "";
-        required DOMString      violatedDirective;
-        required DOMString      effectiveDirective;
-        required DOMString      originalPolicy;
-                 USVString      sourceFile = "";
-                 DOMString      sample = "";
-        required SecurityPolicyViolationEventDisposition disposition;
-        required unsigned short statusCode;
-                 unsigned long  lineNumber = 0;
-                 unsigned long  columnNumber = 0;
+        USVString      documentURI = "";
+        USVString      referrer = "";
+        USVString      blockedURI = "";
+        DOMString      violatedDirective = "";
+        DOMString      effectiveDirective = "";
+        DOMString      originalPolicy = "";
+        USVString      sourceFile = "";
+        DOMString      sample = "";
+        SecurityPolicyViolationEventDisposition disposition = "enforce";
+        unsigned short statusCode = 0;
+        unsigned long  lineNumber = 0;
+        unsigned long  columnNumber = 0;
     };
   </pre>