[Presentation API] Add missing RuntimeEnabled=Presentation to new idl.

Add missing RuntimeEnabled=Presentation annotation to
PresentationConnectionCloseEvent.idl.

BUG=585879
TBR=mlamouri@chromium.org

Review URL: https://codereview.chromium.org/1689453005

Cr-Commit-Position: refs/heads/master@{#374793}

third_party/WebKit/Source/modules/presentation/PresentationConnectionCloseEvent.idl

@@ -8,6 +8,7 @@ enum PresentationConnectionCloseReason { "error", "closed", "wentaway" };
 
 [
     Constructor(DOMString type, PresentationConnectionCloseEventInit eventInitDict),
+    RuntimeEnabled=Presentation
 ] interface PresentationConnectionCloseEvent : Event {
     readonly attribute PresentationConnectionCloseReason reason;
     readonly attribute DOMString message;