Bug #112324 --> don't initialize the view header menu item in the onload handler for the mail

3-pane. This helps start up time in a very small way.

r=bienvenu
rs=sspitzer

mailnews/base/resources/content/mailWindowOverlay.js

@@ -257,6 +257,35 @@ function InitMessageMenu()
   document.commandDispatcher.updateCommands('create-menu-message');
 }
 
+function InitViewHeadersMenu()
+{
+  var id = null;
+  var headerchoice = 1;
+  try 
+  {
+    headerchoice = pref.getIntPref("mail.show_headers");
+  }
+  catch (ex) 
+  {
+    dump("failed to get the header pref\n");
+  }
+
+  switch (headerchoice) 
+  {
+	case 2:	
+		id = "viewallheaders";
+		break;
+	case 1:	
+	default:
+		id = "viewnormalheaders";
+		break;
+  }
+
+  var menuitem = document.getElementById(id);
+  if (menuitem)
+    menuitem.setAttribute("checked", "true"); 
+}
+
 function IsNewsMessage(messageUri)
 {
     if (!messageUri) return false;

mailnews/base/resources/content/mailWindowOverlay.xul

@@ -995,7 +995,7 @@ Rights Reserved.
         </menupopup>
       </menu>
       <menu id="viewheadersmenu" label="&headersMenu.label;" accesskey="&headersMenu.accesskey;">
-        <menupopup>
+        <menupopup  onpopupshowing="InitViewHeadersMenu();">
           <menuitem id="viewallheaders"
            type="radio"
            name="viewheadergroup"

mailnews/base/resources/content/msgMail3PaneWindow.js

@@ -444,45 +444,10 @@ function OnLoadMessenger()
   // FIX ME - later we will be able to use onload from the overlay
   OnLoadMsgHeaderPane();
 
-	var id = null;
-	var headerchoice = null;
+  gHaveLoadedMessage = false;
 
-	try {
-		headerchoice = pref.getIntPref("mail.show_headers");
-	}
-	catch (ex) {
-		dump("failed to get the header pref\n");
-	}
-
-	switch (headerchoice) {
-		case 2:	
-			id = "viewallheaders";
-			break;
-		case 0:
-			id = "viewbriefheaders";
-			break;
-		case 1:	
-			id = "viewnormalheaders";
-			break;
-		default:
-			id = "viewnormalheaders";
-			break;
-	}
-
-	var menuitem = document.getElementById(id);
-
-	try {
-		// not working right yet.  see bug #??????
-		// menuitem.setAttribute("checked", "true"); 
-	}
-	catch (ex) {
-		dump("failed to set the view headers menu item\n");
-	}
-
-	gHaveLoadedMessage = false;
-
-	//Set focus to the Thread Pane the first time the window is opened.
-	SetFocusThreadPane();
+  //Set focus to the Thread Pane the first time the window is opened.
+  SetFocusThreadPane();
 }
 
 function OnUnloadMessenger()