don't do the work for the performance measurements if the "mail.showMessengerPerformance" pref isn't true. sr=bienvenu

mailnews/base/resources/content/commandglue.js

@@ -183,8 +183,11 @@ function ChangeFolderByURI(uri, isThreaded, sortID, sortDirection, viewType)
 	ClearThreadPane();
 	return;
   }
-    
-  gBeforeFolderLoadTime = new Date();
+   
+  if (showPerformance) { 
+    gBeforeFolderLoadTime = new Date();
+  }
+
   gCurrentLoadingFolderURI = uri;
   gNextMessageAfterDelete = null; // forget what message to select, if any
 
@@ -471,7 +474,7 @@ function FindThreadPaneColumnBySortResource(sortID)
 //If it's not true then use the direction passed in.
 function SortThreadPane(column, sortKey, secondarySortKey, toggleCurrentDirection, direction, changeCursor)
 {
-	//dump("In SortThreadPane\n");
+	dump("In SortThreadPane, toggleCurrentDirection = " + toggleCurrentDirection + "\n");
 	var node = document.getElementById(column);
 	if(!node)
 		return false;
@@ -503,18 +506,23 @@ function SortThreadPane(column, sortKey, secondarySortKey, toggleCurrentDirectio
 	SetActiveThreadPaneSortColumn(column);
 
 	var selection = SaveThreadPaneSelection();
-	var beforeSortTime = new Date();
+	var beforeSortTime;
+	if(showPerformance) {
+        beforeSortTime = new Date();
+    }
 
 	if(changeCursor)
 		SetBusyCursor(window, true);
 	var result = SortColumn(node, sortKey, secondarySortKey, direction);
 	if(changeCursor)
 		SetBusyCursor(window, false);
-	var afterSortTime = new Date();
-	var timeToSort = (afterSortTime.getTime() - beforeSortTime.getTime())/1000;
 
-	if(showPerformance)
+	if(showPerformance) {
+	    var afterSortTime = new Date();
+	    var timeToSort = (afterSortTime.getTime() - beforeSortTime.getTime())/1000;
 		dump("timeToSort is " + timeToSort + "seconds\n");
+    }
+
 	RestoreThreadPaneSelection(selection);
 	return result;
 }

mailnews/base/resources/content/msgMail3PaneWindow.js

@@ -21,7 +21,7 @@
 /* This is where functions related to the 3 pane window are kept */
 
 
-var showPerformance;
+var showPerformance = false;
 var msgNavigationService;
 
 var gFolderTree;
@@ -133,18 +133,20 @@ var folderListener = {
 				{
 				  gCurrentLoadingFolderURI = "";
 				  //Now let's select the first new message if there is one
-				  var beforeScrollToNew = new Date();
+                  var beforeScrollToNew;
+				  if(showPerformance) {
+				    beforeScrollToNew = new Date();
+                  }
 				  msgNavigationService.EnsureDocumentIsLoaded(document);
 
 				  ScrollToFirstNewMessage();
-				  var afterScrollToNew = new Date();
-				  var timeToScroll = (afterScrollToNew.getTime() - beforeScrollToNew.getTime())/1000;
 
+				  if(showPerformance) {
+				      var afterScrollToNew = new Date();
+				      var timeToScroll = (afterScrollToNew.getTime() - beforeScrollToNew.getTime())/1000;
 
-				  var afterFolderLoadTime = new Date();
-				  var timeToLoad = (afterFolderLoadTime.getTime() - gBeforeFolderLoadTime.getTime())/1000;
-				  if(showPerformance)
-				  {
+				      var afterFolderLoadTime = new Date();
+				      var timeToLoad = (afterFolderLoadTime.getTime() - gBeforeFolderLoadTime.getTime())/1000;
 					  dump("Time to load " + uri + " is " +  timeToLoad + " seconds\n");
 				  	  dump("of which scrolling to new is" + timeToScroll + "seconds\n");
 				  }
@@ -300,11 +302,9 @@ function OnLoadMessenger()
 	//Set focus to the Thread Pane the first time the window is opened.
 	SetFocusThreadPane();
 
-	var afterLoadMessenger = new Date();
-
-	var timeToLoad = (afterLoadMessenger.getTime() - beforeLoadMessenger.getTime())/1000;
-	if(showPerformance)
-	{
+	if(showPerformance) {
+	  var afterLoadMessenger = new Date();
+	  var timeToLoad = (afterLoadMessenger.getTime() - beforeLoadMessenger.getTime())/1000;
 	  dump("Time in OnLoadMessger is " +  timeToLoad + " seconds\n");
 	}